correction after cherry-pick and merge in last commit
[unres.git] / source / wham / src / energy_p_new.F
1       subroutine etotal(energia,fact)
2       implicit real*8 (a-h,o-z)
3       include 'DIMENSIONS'
4       include 'DIMENSIONS.ZSCOPT'
5
6 #ifndef ISNAN
7       external proc_proc
8 #endif
9 #ifdef WINPGI
10 cMS$ATTRIBUTES C ::  proc_proc
11 #endif
12
13       include 'COMMON.IOUNITS'
14       double precision energia(0:max_ene),energia1(0:max_ene+1)
15 #ifdef MPL
16       include 'COMMON.INFO'
17       external d_vadd
18       integer ready
19 #endif
20       include 'COMMON.FFIELD'
21       include 'COMMON.DERIV'
22       include 'COMMON.INTERACT'
23       include 'COMMON.SBRIDGE'
24       include 'COMMON.CHAIN'
25       double precision fact(6)
26 cd      write(iout, '(a,i2)')'Calling etotal ipot=',ipot
27 cd    print *,'nnt=',nnt,' nct=',nct
28 C
29 C Compute the side-chain and electrostatic interaction energy
30 C
31       goto (101,102,103,104,105) ipot
32 C Lennard-Jones potential.
33   101 call elj(evdw,evdw_t)
34 cd    print '(a)','Exit ELJ'
35       goto 106
36 C Lennard-Jones-Kihara potential (shifted).
37   102 call eljk(evdw,evdw_t)
38       goto 106
39 C Berne-Pechukas potential (dilated LJ, angular dependence).
40   103 call ebp(evdw,evdw_t)
41       goto 106
42 C Gay-Berne potential (shifted LJ, angular dependence).
43   104 call egb(evdw,evdw_t)
44       goto 106
45 C Gay-Berne-Vorobjev potential (shifted LJ, angular dependence).
46   105 call egbv(evdw,evdw_t)
47 C
48 C Calculate electrostatic (H-bonding) energy of the main chain.
49 C
50   106 call eelec(ees,evdw1,eel_loc,eello_turn3,eello_turn4)
51 C
52 C Calculate excluded-volume interaction energy between peptide groups
53 C and side chains.
54 C
55       call escp(evdw2,evdw2_14)
56 c
57 c Calculate the bond-stretching energy
58 c
59       call ebond(estr)
60 c      write (iout,*) "estr",estr
61
62 C Calculate the disulfide-bridge and other energy and the contributions
63 C from other distance constraints.
64 cd    print *,'Calling EHPB'
65       call edis(ehpb)
66 cd    print *,'EHPB exitted succesfully.'
67 C
68 C Calculate the virtual-bond-angle energy.
69 C
70       call ebend(ebe)
71 cd    print *,'Bend energy finished.'
72 C
73 C Calculate the SC local energy.
74 C
75       call esc(escloc)
76 cd    print *,'SCLOC energy finished.'
77 C
78 C Calculate the virtual-bond torsional energy.
79 C
80 cd    print *,'nterm=',nterm
81       call etor(etors,edihcnstr,fact(1))
82 C
83 C 6/23/01 Calculate double-torsional energy
84 C
85       call etor_d(etors_d,fact(2))
86 C
87 C 21/5/07 Calculate local sicdechain correlation energy
88 C
89       call eback_sc_corr(esccor)
90
91 C 12/1/95 Multi-body terms
92 C
93       n_corr=0
94       n_corr1=0
95       if (wcorr4.gt.0.0d0 .or. wcorr5.gt.0.0d0 .or. wcorr6.gt.0.0d0 
96      &    .or. wturn6.gt.0.0d0) then
97 c         print *,"calling multibody_eello"
98          call multibody_eello(ecorr,ecorr5,ecorr6,eturn6,n_corr,n_corr1)
99 c         write (*,*) 'n_corr=',n_corr,' n_corr1=',n_corr1
100 c         print *,ecorr,ecorr5,ecorr6,eturn6
101       endif
102       if (wcorr4.eq.0.0d0 .and. wcorr.gt.0.0d0) then
103          call multibody_hb(ecorr,ecorr5,ecorr6,n_corr,n_corr1)
104       endif
105 c      write (iout,*) "ft(6)",fact(6)," evdw",evdw," evdw_t",evdw_t
106 #ifdef SPLITELE
107       etot=wsc*(evdw+fact(6)*evdw_t)+wscp*evdw2+welec*fact(1)*ees
108      & +wvdwpp*evdw1
109      & +wang*ebe+wtor*fact(1)*etors+wscloc*escloc
110      & +wstrain*ehpb+wcorr*fact(3)*ecorr+wcorr5*fact(4)*ecorr5
111      & +wcorr6*fact(5)*ecorr6+wturn4*fact(3)*eello_turn4
112      & +wturn3*fact(2)*eello_turn3+wturn6*fact(5)*eturn6
113      & +wel_loc*fact(2)*eel_loc+edihcnstr+wtor_d*fact(2)*etors_d
114      & +wbond*estr+wsccor*fact(1)*esccor
115 #else
116       etot=wsc*(evdw+fact(6)*evdw_t)+wscp*evdw2
117      & +welec*fact(1)*(ees+evdw1)
118      & +wang*ebe+wtor*fact(1)*etors+wscloc*escloc
119      & +wstrain*ehpb+wcorr*fact(3)*ecorr+wcorr5*fact(4)*ecorr5
120      & +wcorr6*fact(5)*ecorr6+wturn4*fact(3)*eello_turn4
121      & +wturn3*fact(2)*eello_turn3+wturn6*fact(5)*eturn6
122      & +wel_loc*fact(2)*eel_loc+edihcnstr+wtor_d*fact(2)*etors_d
123      & +wbond*estr+wsccor*fact(1)*esccor
124 #endif
125       energia(0)=etot
126       energia(1)=evdw
127 #ifdef SCP14
128       energia(2)=evdw2-evdw2_14
129       energia(17)=evdw2_14
130 #else
131       energia(2)=evdw2
132       energia(17)=0.0d0
133 #endif
134 #ifdef SPLITELE
135       energia(3)=ees
136       energia(16)=evdw1
137 #else
138       energia(3)=ees+evdw1
139       energia(16)=0.0d0
140 #endif
141       energia(4)=ecorr
142       energia(5)=ecorr5
143       energia(6)=ecorr6
144       energia(7)=eel_loc
145       energia(8)=eello_turn3
146       energia(9)=eello_turn4
147       energia(10)=eturn6
148       energia(11)=ebe
149       energia(12)=escloc
150       energia(13)=etors
151       energia(14)=etors_d
152       energia(15)=ehpb
153       energia(18)=estr
154       energia(19)=esccor
155       energia(20)=edihcnstr
156       energia(21)=evdw_t
157 c      if (dyn_ss) call dyn_set_nss
158 c detecting NaNQ
159 #ifdef ISNAN
160 #ifdef AIX
161       if (isnan(etot).ne.0) energia(0)=1.0d+99
162 #else
163       if (isnan(etot)) energia(0)=1.0d+99
164 #endif
165 #else
166       i=0
167 #ifdef WINPGI
168       idumm=proc_proc(etot,i)
169 #else
170       call proc_proc(etot,i)
171 #endif
172       if(i.eq.1)energia(0)=1.0d+99
173 #endif
174 #ifdef MPL
175 c     endif
176 #endif
177       if (calc_grad) then
178 C
179 C Sum up the components of the Cartesian gradient.
180 C
181 #ifdef SPLITELE
182       do i=1,nct
183         do j=1,3
184           gradc(j,i,icg)=wsc*gvdwc(j,i)+wscp*gvdwc_scp(j,i)+
185      &                welec*fact(1)*gelc(j,i)+wvdwpp*gvdwpp(j,i)+
186      &                wbond*gradb(j,i)+
187      &                wstrain*ghpbc(j,i)+
188      &                wcorr*fact(3)*gradcorr(j,i)+
189      &                wel_loc*fact(2)*gel_loc(j,i)+
190      &                wturn3*fact(2)*gcorr3_turn(j,i)+
191      &                wturn4*fact(3)*gcorr4_turn(j,i)+
192      &                wcorr5*fact(4)*gradcorr5(j,i)+
193      &                wcorr6*fact(5)*gradcorr6(j,i)+
194      &                wturn6*fact(5)*gcorr6_turn(j,i)+
195      &                wsccor*fact(2)*gsccorc(j,i)
196           gradx(j,i,icg)=wsc*gvdwx(j,i)+wscp*gradx_scp(j,i)+
197      &                  wbond*gradbx(j,i)+
198      &                  wstrain*ghpbx(j,i)+wcorr*gradxorr(j,i)+
199      &                  wsccor*fact(2)*gsccorx(j,i)
200         enddo
201 #else
202       do i=1,nct
203         do j=1,3
204           gradc(j,i,icg)=wsc*gvdwc(j,i)+wscp*gvdwc_scp(j,i)+
205      &                welec*fact(1)*gelc(j,i)+wstrain*ghpbc(j,i)+
206      &                wbond*gradb(j,i)+
207      &                wcorr*fact(3)*gradcorr(j,i)+
208      &                wel_loc*fact(2)*gel_loc(j,i)+
209      &                wturn3*fact(2)*gcorr3_turn(j,i)+
210      &                wturn4*fact(3)*gcorr4_turn(j,i)+
211      &                wcorr5*fact(4)*gradcorr5(j,i)+
212      &                wcorr6*fact(5)*gradcorr6(j,i)+
213      &                wturn6*fact(5)*gcorr6_turn(j,i)+
214      &                wsccor*fact(2)*gsccorc(j,i)
215           gradx(j,i,icg)=wsc*gvdwx(j,i)+wscp*gradx_scp(j,i)+
216      &                  wbond*gradbx(j,i)+
217      &                  wstrain*ghpbx(j,i)+wcorr*gradxorr(j,i)+
218      &                  wsccor*fact(1)*gsccorx(j,i)
219         enddo
220 #endif
221       enddo
222
223
224       do i=1,nres-3
225         gloc(i,icg)=gloc(i,icg)+wcorr*fact(3)*gcorr_loc(i)
226      &   +wcorr5*fact(4)*g_corr5_loc(i)
227      &   +wcorr6*fact(5)*g_corr6_loc(i)
228      &   +wturn4*fact(3)*gel_loc_turn4(i)
229      &   +wturn3*fact(2)*gel_loc_turn3(i)
230      &   +wturn6*fact(5)*gel_loc_turn6(i)
231      &   +wel_loc*fact(2)*gel_loc_loc(i)
232      &   +wsccor*fact(1)*gsccor_loc(i)
233       enddo
234       endif
235       return
236       end
237 C------------------------------------------------------------------------
238       subroutine enerprint(energia,fact)
239       implicit real*8 (a-h,o-z)
240       include 'DIMENSIONS'
241       include 'DIMENSIONS.ZSCOPT'
242       include 'COMMON.IOUNITS'
243       include 'COMMON.FFIELD'
244       include 'COMMON.SBRIDGE'
245       double precision energia(0:max_ene),fact(6)
246       etot=energia(0)
247       evdw=energia(1)+fact(6)*energia(21)
248 #ifdef SCP14
249       evdw2=energia(2)+energia(17)
250 #else
251       evdw2=energia(2)
252 #endif
253       ees=energia(3)
254 #ifdef SPLITELE
255       evdw1=energia(16)
256 #endif
257       ecorr=energia(4)
258       ecorr5=energia(5)
259       ecorr6=energia(6)
260       eel_loc=energia(7)
261       eello_turn3=energia(8)
262       eello_turn4=energia(9)
263       eello_turn6=energia(10)
264       ebe=energia(11)
265       escloc=energia(12)
266       etors=energia(13)
267       etors_d=energia(14)
268       ehpb=energia(15)
269       esccor=energia(19)
270       edihcnstr=energia(20)
271       estr=energia(18)
272 #ifdef SPLITELE
273       write (iout,10) evdw,wsc,evdw2,wscp,ees,welec*fact(1),evdw1,
274      &  wvdwpp,
275      &  estr,wbond,ebe,wang,escloc,wscloc,etors,wtor*fact(1),
276      &  etors_d,wtor_d*fact(2),ehpb,wstrain,
277      &  ecorr,wcorr*fact(3),ecorr5,wcorr5*fact(4),ecorr6,wcorr6*fact(5),
278      &  eel_loc,wel_loc*fact(2),eello_turn3,wturn3*fact(2),
279      &  eello_turn4,wturn4*fact(3),eello_turn6,wturn6*fact(5),
280      &  esccor,wsccor*fact(1),edihcnstr,ebr*nss,etot
281    10 format (/'Virtual-chain energies:'//
282      & 'EVDW=  ',1pE16.6,' WEIGHT=',1pD16.6,' (SC-SC)'/
283      & 'EVDW2= ',1pE16.6,' WEIGHT=',1pD16.6,' (SC-p)'/
284      & 'EES=   ',1pE16.6,' WEIGHT=',1pD16.6,' (p-p elec)'/
285      & 'EVDWPP=',1pE16.6,' WEIGHT=',1pD16.6,' (p-p VDW)'/
286      & 'ESTR=  ',1pE16.6,' WEIGHT=',1pD16.6,' (stretching)'/
287      & 'EBE=   ',1pE16.6,' WEIGHT=',1pD16.6,' (bending)'/
288      & 'ESC=   ',1pE16.6,' WEIGHT=',1pD16.6,' (SC local)'/
289      & 'ETORS= ',1pE16.6,' WEIGHT=',1pD16.6,' (torsional)'/
290      & 'ETORSD=',1pE16.6,' WEIGHT=',1pD16.6,' (double torsional)'/
291      & 'EHBP=  ',1pE16.6,' WEIGHT=',1pD16.6,
292      & ' (SS bridges & dist. cnstr.)'/
293      & 'ECORR4=',1pE16.6,' WEIGHT=',1pD16.6,' (multi-body)'/
294      & 'ECORR5=',1pE16.6,' WEIGHT=',1pD16.6,' (multi-body)'/
295      & 'ECORR6=',1pE16.6,' WEIGHT=',1pD16.6,' (multi-body)'/
296      & 'EELLO= ',1pE16.6,' WEIGHT=',1pD16.6,' (electrostatic-local)'/
297      & 'ETURN3=',1pE16.6,' WEIGHT=',1pD16.6,' (turns, 3rd order)'/
298      & 'ETURN4=',1pE16.6,' WEIGHT=',1pD16.6,' (turns, 4th order)'/
299      & 'ETURN6=',1pE16.6,' WEIGHT=',1pD16.6,' (turns, 6th order)'/
300      & 'ESCCOR=',1pE16.6,' WEIGHT=',1pD16.6,' (backbone-rotamer corr)'/
301      & 'EDIHC= ',1pE16.6,' (dihedral angle constraints)'/
302      & 'ESS=   ',1pE16.6,' (disulfide-bridge intrinsic energy)'/ 
303      & 'ETOT=  ',1pE16.6,' (total)')
304 #else
305       write (iout,10) evdw,wsc,evdw2,wscp,ees,welec*fact(1),estr,wbond,
306      &  ebe,wang,escloc,wscloc,etors,wtor*fact(1),etors_d,wtor_d*fact2,
307      &  ehpb,wstrain,ecorr,wcorr*fact(3),ecorr5,wcorr5*fact(4),
308      &  ecorr6,wcorr6*fact(5),eel_loc,wel_loc*fact(2),
309      &  eello_turn3,wturn3*fact(2),eello_turn4,wturn4*fact(3),
310      &  eello_turn6,wturn6*fact(5),esccor*fact(1),wsccor,
311      &  edihcnstr,ebr*nss,etot
312    10 format (/'Virtual-chain energies:'//
313      & 'EVDW=  ',1pE16.6,' WEIGHT=',1pD16.6,' (SC-SC)'/
314      & 'EVDW2= ',1pE16.6,' WEIGHT=',1pD16.6,' (SC-p)'/
315      & 'EES=   ',1pE16.6,' WEIGHT=',1pD16.6,' (p-p)'/
316      & 'ESTR=  ',1pE16.6,' WEIGHT=',1pD16.6,' (stretching)'/
317      & 'EBE=   ',1pE16.6,' WEIGHT=',1pD16.6,' (bending)'/
318      & 'ESC=   ',1pE16.6,' WEIGHT=',1pD16.6,' (SC local)'/
319      & 'ETORS= ',1pE16.6,' WEIGHT=',1pD16.6,' (torsional)'/
320      & 'ETORSD=',1pE16.6,' WEIGHT=',1pD16.6,' (double torsional)'/
321      & 'EHBP=  ',1pE16.6,' WEIGHT=',1pD16.6,
322      & ' (SS bridges & dist. cnstr.)'/
323      & 'ECORR4=',1pE16.6,' WEIGHT=',1pD16.6,' (multi-body)'/
324      & 'ECORR5=',1pE16.6,' WEIGHT=',1pD16.6,' (multi-body)'/
325      & 'ECORR6=',1pE16.6,' WEIGHT=',1pD16.6,' (multi-body)'/
326      & 'EELLO= ',1pE16.6,' WEIGHT=',1pD16.6,' (electrostatic-local)'/
327      & 'ETURN3=',1pE16.6,' WEIGHT=',1pD16.6,' (turns, 3rd order)'/
328      & 'ETURN4=',1pE16.6,' WEIGHT=',1pD16.6,' (turns, 4th order)'/
329      & 'ETURN6=',1pE16.6,' WEIGHT=',1pD16.6,' (turns, 6th order)'/
330      & 'ESCCOR=',1pE16.6,' WEIGHT=',1pD16.6,' (backbone-rotamer corr)'/
331      & 'EDIHC= ',1pE16.6,' (dihedral angle constraints)'/
332      & 'ESS=   ',1pE16.6,' (disulfide-bridge intrinsic energy)'/ 
333      & 'ETOT=  ',1pE16.6,' (total)')
334 #endif
335       return
336       end
337 C-----------------------------------------------------------------------
338       subroutine elj(evdw,evdw_t)
339 C
340 C This subroutine calculates the interaction energy of nonbonded side chains
341 C assuming the LJ potential of interaction.
342 C
343       implicit real*8 (a-h,o-z)
344       include 'DIMENSIONS'
345       include 'DIMENSIONS.ZSCOPT'
346       include "DIMENSIONS.COMPAR"
347       parameter (accur=1.0d-10)
348       include 'COMMON.GEO'
349       include 'COMMON.VAR'
350       include 'COMMON.LOCAL'
351       include 'COMMON.CHAIN'
352       include 'COMMON.DERIV'
353       include 'COMMON.INTERACT'
354       include 'COMMON.TORSION'
355       include 'COMMON.ENEPS'
356       include 'COMMON.SBRIDGE'
357       include 'COMMON.NAMES'
358       include 'COMMON.IOUNITS'
359       include 'COMMON.CONTACTS'
360       dimension gg(3)
361       integer icant
362       external icant
363 cd    print *,'Entering ELJ nnt=',nnt,' nct=',nct,' expon=',expon
364       do i=1,210
365         do j=1,2
366           eneps_temp(j,i)=0.0d0
367         enddo
368       enddo
369       evdw=0.0D0
370       evdw_t=0.0d0
371       do i=iatsc_s,iatsc_e
372         itypi=itype(i)
373         itypi1=itype(i+1)
374         xi=c(1,nres+i)
375         yi=c(2,nres+i)
376         zi=c(3,nres+i)
377 C Change 12/1/95
378         num_conti=0
379 C
380 C Calculate SC interaction energy.
381 C
382         do iint=1,nint_gr(i)
383 cd        write (iout,*) 'i=',i,' iint=',iint,' istart=',istart(i,iint),
384 cd   &                  'iend=',iend(i,iint)
385           do j=istart(i,iint),iend(i,iint)
386             itypj=itype(j)
387             xj=c(1,nres+j)-xi
388             yj=c(2,nres+j)-yi
389             zj=c(3,nres+j)-zi
390 C Change 12/1/95 to calculate four-body interactions
391             rij=xj*xj+yj*yj+zj*zj
392             rrij=1.0D0/rij
393 c           write (iout,*)'i=',i,' j=',j,' itypi=',itypi,' itypj=',itypj
394             eps0ij=eps(itypi,itypj)
395             fac=rrij**expon2
396             e1=fac*fac*aa(itypi,itypj)
397             e2=fac*bb(itypi,itypj)
398             evdwij=e1+e2
399             ij=icant(itypi,itypj)
400             eneps_temp(1,ij)=eneps_temp(1,ij)+e1/dabs(eps0ij)
401             eneps_temp(2,ij)=eneps_temp(2,ij)+e2/eps0ij
402 cd          sigm=dabs(aa(itypi,itypj)/bb(itypi,itypj))**(1.0D0/6.0D0)
403 cd          epsi=bb(itypi,itypj)**2/aa(itypi,itypj)
404 cd          write (iout,'(2(a3,i3,2x),6(1pd12.4)/2(3(1pd12.4),5x)/)')
405 cd   &        restyp(itypi),i,restyp(itypj),j,aa(itypi,itypj),
406 cd   &        bb(itypi,itypj),1.0D0/dsqrt(rrij),evdwij,epsi,sigm,
407 cd   &        (c(k,i),k=1,3),(c(k,j),k=1,3)
408             if (bb(itypi,itypj).gt.0.0d0) then
409               evdw=evdw+evdwij
410             else
411               evdw_t=evdw_t+evdwij
412             endif
413             if (calc_grad) then
414
415 C Calculate the components of the gradient in DC and X
416 C
417             fac=-rrij*(e1+evdwij)
418             gg(1)=xj*fac
419             gg(2)=yj*fac
420             gg(3)=zj*fac
421             do k=1,3
422               gvdwx(k,i)=gvdwx(k,i)-gg(k)
423               gvdwx(k,j)=gvdwx(k,j)+gg(k)
424             enddo
425             do k=i,j-1
426               do l=1,3
427                 gvdwc(l,k)=gvdwc(l,k)+gg(l)
428               enddo
429             enddo
430             endif
431 C
432 C 12/1/95, revised on 5/20/97
433 C
434 C Calculate the contact function. The ith column of the array JCONT will 
435 C contain the numbers of atoms that make contacts with the atom I (of numbers
436 C greater than I). The arrays FACONT and GACONT will contain the values of
437 C the contact function and its derivative.
438 C
439 C Uncomment next line, if the correlation interactions include EVDW explicitly.
440 c           if (j.gt.i+1 .and. evdwij.le.0.0D0) then
441 C Uncomment next line, if the correlation interactions are contact function only
442             if (j.gt.i+1.and. eps0ij.gt.0.0D0) then
443               rij=dsqrt(rij)
444               sigij=sigma(itypi,itypj)
445               r0ij=rs0(itypi,itypj)
446 C
447 C Check whether the SC's are not too far to make a contact.
448 C
449               rcut=1.5d0*r0ij
450               call gcont(rij,rcut,1.0d0,0.2d0*rcut,fcont,fprimcont)
451 C Add a new contact, if the SC's are close enough, but not too close (r<sigma).
452 C
453               if (fcont.gt.0.0D0) then
454 C If the SC-SC distance if close to sigma, apply spline.
455 cAdam           call gcont(-rij,-1.03d0*sigij,2.0d0*sigij,1.0d0,
456 cAdam &             fcont1,fprimcont1)
457 cAdam           fcont1=1.0d0-fcont1
458 cAdam           if (fcont1.gt.0.0d0) then
459 cAdam             fprimcont=fprimcont*fcont1+fcont*fprimcont1
460 cAdam             fcont=fcont*fcont1
461 cAdam           endif
462 C Uncomment following 4 lines to have the geometric average of the epsilon0's
463 cga             eps0ij=1.0d0/dsqrt(eps0ij)
464 cga             do k=1,3
465 cga               gg(k)=gg(k)*eps0ij
466 cga             enddo
467 cga             eps0ij=-evdwij*eps0ij
468 C Uncomment for AL's type of SC correlation interactions.
469 cadam           eps0ij=-evdwij
470                 num_conti=num_conti+1
471                 jcont(num_conti,i)=j
472                 facont(num_conti,i)=fcont*eps0ij
473                 fprimcont=eps0ij*fprimcont/rij
474                 fcont=expon*fcont
475 cAdam           gacont(1,num_conti,i)=-fprimcont*xj+fcont*gg(1)
476 cAdam           gacont(2,num_conti,i)=-fprimcont*yj+fcont*gg(2)
477 cAdam           gacont(3,num_conti,i)=-fprimcont*zj+fcont*gg(3)
478 C Uncomment following 3 lines for Skolnick's type of SC correlation.
479                 gacont(1,num_conti,i)=-fprimcont*xj
480                 gacont(2,num_conti,i)=-fprimcont*yj
481                 gacont(3,num_conti,i)=-fprimcont*zj
482 cd              write (iout,'(2i5,2f10.5)') i,j,rij,facont(num_conti,i)
483 cd              write (iout,'(2i3,3f10.5)') 
484 cd   &           i,j,(gacont(kk,num_conti,i),kk=1,3)
485               endif
486             endif
487           enddo      ! j
488         enddo        ! iint
489 C Change 12/1/95
490         num_cont(i)=num_conti
491       enddo          ! i
492       if (calc_grad) then
493       do i=1,nct
494         do j=1,3
495           gvdwc(j,i)=expon*gvdwc(j,i)
496           gvdwx(j,i)=expon*gvdwx(j,i)
497         enddo
498       enddo
499       endif
500 C******************************************************************************
501 C
502 C                              N O T E !!!
503 C
504 C To save time, the factor of EXPON has been extracted from ALL components
505 C of GVDWC and GRADX. Remember to multiply them by this factor before further 
506 C use!
507 C
508 C******************************************************************************
509       return
510       end
511 C-----------------------------------------------------------------------------
512       subroutine eljk(evdw,evdw_t)
513 C
514 C This subroutine calculates the interaction energy of nonbonded side chains
515 C assuming the LJK potential of interaction.
516 C
517       implicit real*8 (a-h,o-z)
518       include 'DIMENSIONS'
519       include 'DIMENSIONS.ZSCOPT'
520       include "DIMENSIONS.COMPAR"
521       include 'COMMON.GEO'
522       include 'COMMON.VAR'
523       include 'COMMON.LOCAL'
524       include 'COMMON.CHAIN'
525       include 'COMMON.DERIV'
526       include 'COMMON.INTERACT'
527       include 'COMMON.ENEPS'
528       include 'COMMON.IOUNITS'
529       include 'COMMON.NAMES'
530       dimension gg(3)
531       logical scheck
532       integer icant
533       external icant
534 c     print *,'Entering ELJK nnt=',nnt,' nct=',nct,' expon=',expon
535       do i=1,210
536         do j=1,2
537           eneps_temp(j,i)=0.0d0
538         enddo
539       enddo
540       evdw=0.0D0
541       evdw_t=0.0d0
542       do i=iatsc_s,iatsc_e
543         itypi=itype(i)
544         itypi1=itype(i+1)
545         xi=c(1,nres+i)
546         yi=c(2,nres+i)
547         zi=c(3,nres+i)
548 C
549 C Calculate SC interaction energy.
550 C
551         do iint=1,nint_gr(i)
552           do j=istart(i,iint),iend(i,iint)
553             itypj=itype(j)
554             xj=c(1,nres+j)-xi
555             yj=c(2,nres+j)-yi
556             zj=c(3,nres+j)-zi
557             rrij=1.0D0/(xj*xj+yj*yj+zj*zj)
558             fac_augm=rrij**expon
559             e_augm=augm(itypi,itypj)*fac_augm
560             r_inv_ij=dsqrt(rrij)
561             rij=1.0D0/r_inv_ij 
562             r_shift_inv=1.0D0/(rij+r0(itypi,itypj)-sigma(itypi,itypj))
563             fac=r_shift_inv**expon
564             e1=fac*fac*aa(itypi,itypj)
565             e2=fac*bb(itypi,itypj)
566             evdwij=e_augm+e1+e2
567             ij=icant(itypi,itypj)
568             eneps_temp(1,ij)=eneps_temp(1,ij)+(e1+a_augm)
569      &        /dabs(eps(itypi,itypj))
570             eneps_temp(2,ij)=eneps_temp(2,ij)+e2/eps(itypi,itypj)
571 cd          sigm=dabs(aa(itypi,itypj)/bb(itypi,itypj))**(1.0D0/6.0D0)
572 cd          epsi=bb(itypi,itypj)**2/aa(itypi,itypj)
573 cd          write (iout,'(2(a3,i3,2x),8(1pd12.4)/2(3(1pd12.4),5x)/)')
574 cd   &        restyp(itypi),i,restyp(itypj),j,aa(itypi,itypj),
575 cd   &        bb(itypi,itypj),augm(itypi,itypj),epsi,sigm,
576 cd   &        sigma(itypi,itypj),1.0D0/dsqrt(rrij),evdwij,
577 cd   &        (c(k,i),k=1,3),(c(k,j),k=1,3)
578             if (bb(itypi,itypj).gt.0.0d0) then
579               evdw=evdw+evdwij
580             else 
581               evdw_t=evdw_t+evdwij
582             endif
583             if (calc_grad) then
584
585 C Calculate the components of the gradient in DC and X
586 C
587             fac=-2.0D0*rrij*e_augm-r_inv_ij*r_shift_inv*(e1+e1+e2)
588             gg(1)=xj*fac
589             gg(2)=yj*fac
590             gg(3)=zj*fac
591             do k=1,3
592               gvdwx(k,i)=gvdwx(k,i)-gg(k)
593               gvdwx(k,j)=gvdwx(k,j)+gg(k)
594             enddo
595             do k=i,j-1
596               do l=1,3
597                 gvdwc(l,k)=gvdwc(l,k)+gg(l)
598               enddo
599             enddo
600             endif
601           enddo      ! j
602         enddo        ! iint
603       enddo          ! i
604       if (calc_grad) then
605       do i=1,nct
606         do j=1,3
607           gvdwc(j,i)=expon*gvdwc(j,i)
608           gvdwx(j,i)=expon*gvdwx(j,i)
609         enddo
610       enddo
611       endif
612       return
613       end
614 C-----------------------------------------------------------------------------
615       subroutine ebp(evdw,evdw_t)
616 C
617 C This subroutine calculates the interaction energy of nonbonded side chains
618 C assuming the Berne-Pechukas potential of interaction.
619 C
620       implicit real*8 (a-h,o-z)
621       include 'DIMENSIONS'
622       include 'DIMENSIONS.ZSCOPT'
623       include "DIMENSIONS.COMPAR"
624       include 'COMMON.GEO'
625       include 'COMMON.VAR'
626       include 'COMMON.LOCAL'
627       include 'COMMON.CHAIN'
628       include 'COMMON.DERIV'
629       include 'COMMON.NAMES'
630       include 'COMMON.INTERACT'
631       include 'COMMON.ENEPS'
632       include 'COMMON.IOUNITS'
633       include 'COMMON.CALC'
634       common /srutu/ icall
635 c     double precision rrsave(maxdim)
636       logical lprn
637       integer icant
638       external icant
639       do i=1,210
640         do j=1,2
641           eneps_temp(j,i)=0.0d0
642         enddo
643       enddo
644       evdw=0.0D0
645       evdw_t=0.0d0
646 c     print *,'Entering EBP nnt=',nnt,' nct=',nct,' expon=',expon
647 c     if (icall.eq.0) then
648 c       lprn=.true.
649 c     else
650         lprn=.false.
651 c     endif
652       ind=0
653       do i=iatsc_s,iatsc_e
654         itypi=itype(i)
655         itypi1=itype(i+1)
656         xi=c(1,nres+i)
657         yi=c(2,nres+i)
658         zi=c(3,nres+i)
659         dxi=dc_norm(1,nres+i)
660         dyi=dc_norm(2,nres+i)
661         dzi=dc_norm(3,nres+i)
662         dsci_inv=vbld_inv(i+nres)
663 C
664 C Calculate SC interaction energy.
665 C
666         do iint=1,nint_gr(i)
667           do j=istart(i,iint),iend(i,iint)
668             ind=ind+1
669             itypj=itype(j)
670             dscj_inv=vbld_inv(j+nres)
671             chi1=chi(itypi,itypj)
672             chi2=chi(itypj,itypi)
673             chi12=chi1*chi2
674             chip1=chip(itypi)
675             chip2=chip(itypj)
676             chip12=chip1*chip2
677             alf1=alp(itypi)
678             alf2=alp(itypj)
679             alf12=0.5D0*(alf1+alf2)
680 C For diagnostics only!!!
681 c           chi1=0.0D0
682 c           chi2=0.0D0
683 c           chi12=0.0D0
684 c           chip1=0.0D0
685 c           chip2=0.0D0
686 c           chip12=0.0D0
687 c           alf1=0.0D0
688 c           alf2=0.0D0
689 c           alf12=0.0D0
690             xj=c(1,nres+j)-xi
691             yj=c(2,nres+j)-yi
692             zj=c(3,nres+j)-zi
693             dxj=dc_norm(1,nres+j)
694             dyj=dc_norm(2,nres+j)
695             dzj=dc_norm(3,nres+j)
696             rrij=1.0D0/(xj*xj+yj*yj+zj*zj)
697 cd          if (icall.eq.0) then
698 cd            rrsave(ind)=rrij
699 cd          else
700 cd            rrij=rrsave(ind)
701 cd          endif
702             rij=dsqrt(rrij)
703 C Calculate the angle-dependent terms of energy & contributions to derivatives.
704             call sc_angular
705 C Calculate whole angle-dependent part of epsilon and contributions
706 C to its derivatives
707             fac=(rrij*sigsq)**expon2
708             e1=fac*fac*aa(itypi,itypj)
709             e2=fac*bb(itypi,itypj)
710             evdwij=eps1*eps2rt*eps3rt*(e1+e2)
711             eps2der=evdwij*eps3rt
712             eps3der=evdwij*eps2rt
713             evdwij=evdwij*eps2rt*eps3rt
714             ij=icant(itypi,itypj)
715             aux=eps1*eps2rt**2*eps3rt**2
716             eneps_temp(1,ij)=eneps_temp(1,ij)+e1*aux
717      &        /dabs(eps(itypi,itypj))
718             eneps_temp(2,ij)=eneps_temp(2,ij)+e2*aux/eps(itypi,itypj)
719             if (bb(itypi,itypj).gt.0.0d0) then
720               evdw=evdw+evdwij
721             else
722               evdw_t=evdw_t+evdwij
723             endif
724             if (calc_grad) then
725             if (lprn) then
726             sigm=dabs(aa(itypi,itypj)/bb(itypi,itypj))**(1.0D0/6.0D0)
727             epsi=bb(itypi,itypj)**2/aa(itypi,itypj)
728 cd            write (iout,'(2(a3,i3,2x),15(0pf7.3))')
729 cd     &        restyp(itypi),i,restyp(itypj),j,
730 cd     &        epsi,sigm,chi1,chi2,chip1,chip2,
731 cd     &        eps1,eps2rt**2,eps3rt**2,1.0D0/dsqrt(sigsq),
732 cd     &        om1,om2,om12,1.0D0/dsqrt(rrij),
733 cd     &        evdwij
734             endif
735 C Calculate gradient components.
736             e1=e1*eps1*eps2rt**2*eps3rt**2
737             fac=-expon*(e1+evdwij)
738             sigder=fac/sigsq
739             fac=rrij*fac
740 C Calculate radial part of the gradient
741             gg(1)=xj*fac
742             gg(2)=yj*fac
743             gg(3)=zj*fac
744 C Calculate the angular part of the gradient and sum add the contributions
745 C to the appropriate components of the Cartesian gradient.
746             call sc_grad
747             endif
748           enddo      ! j
749         enddo        ! iint
750       enddo          ! i
751 c     stop
752       return
753       end
754 C-----------------------------------------------------------------------------
755       subroutine egb(evdw,evdw_t)
756 C
757 C This subroutine calculates the interaction energy of nonbonded side chains
758 C assuming the Gay-Berne potential of interaction.
759 C
760       implicit real*8 (a-h,o-z)
761       include 'DIMENSIONS'
762       include 'DIMENSIONS.ZSCOPT'
763       include "DIMENSIONS.COMPAR"
764       include 'COMMON.GEO'
765       include 'COMMON.VAR'
766       include 'COMMON.LOCAL'
767       include 'COMMON.CHAIN'
768       include 'COMMON.DERIV'
769       include 'COMMON.NAMES'
770       include 'COMMON.INTERACT'
771       include 'COMMON.ENEPS'
772       include 'COMMON.IOUNITS'
773       include 'COMMON.CALC'
774       include 'COMMON.SBRIDGE'
775       logical lprn
776       common /srutu/icall
777       integer icant
778       external icant
779       do i=1,210
780         do j=1,2
781           eneps_temp(j,i)=0.0d0
782         enddo
783       enddo
784 c     print *,'Entering EGB nnt=',nnt,' nct=',nct,' expon=',expon
785       evdw=0.0D0
786       evdw_t=0.0d0
787       lprn=.false.
788 c      if (icall.gt.0) lprn=.true.
789       ind=0
790       do i=iatsc_s,iatsc_e
791         itypi=itype(i)
792         itypi1=itype(i+1)
793         xi=c(1,nres+i)
794         yi=c(2,nres+i)
795         zi=c(3,nres+i)
796         dxi=dc_norm(1,nres+i)
797         dyi=dc_norm(2,nres+i)
798         dzi=dc_norm(3,nres+i)
799         dsci_inv=vbld_inv(i+nres)
800 C
801 C Calculate SC interaction energy.
802 C
803         do iint=1,nint_gr(i)
804           do j=istart(i,iint),iend(i,iint)
805 C in case of diagnostics    write (iout,*) "TU SZUKAJ",i,j,dyn_ss_mask(i),dyn_ss_mask(j)
806 C /06/28/2013 Adasko: In case of dyn_ss - dynamic disulfide bond
807 C formation no electrostatic interactions should be calculated. If it
808 C would be allowed NaN would appear
809             IF (dyn_ss_mask(i).and.dyn_ss_mask(j)) THEN
810 C /06/28/2013 Adasko: dyn_ss_mask is logical statement wheather this Cys
811 C residue can or cannot form disulfide bond. There is still bug allowing
812 C Cys...Cys...Cys bond formation
813               call dyn_ssbond_ene(i,j,evdwij)
814 C /06/28/2013 Adasko: dyn_ssbond_ene is dynamic SS bond foration energy
815 C function in ssMD.F
816               evdw=evdw+evdwij
817 c              if (energy_dec) write (iout,'(a6,2i5,0pf7.3,a3)')
818 c     &                        'evdw',i,j,evdwij,' ss'
819             ELSE
820             ind=ind+1
821             itypj=itype(j)
822             dscj_inv=vbld_inv(j+nres)
823             sig0ij=sigma(itypi,itypj)
824             chi1=chi(itypi,itypj)
825             chi2=chi(itypj,itypi)
826             chi12=chi1*chi2
827             chip1=chip(itypi)
828             chip2=chip(itypj)
829             chip12=chip1*chip2
830             alf1=alp(itypi)
831             alf2=alp(itypj)
832             alf12=0.5D0*(alf1+alf2)
833 C For diagnostics only!!!
834 c           chi1=0.0D0
835 c           chi2=0.0D0
836 c           chi12=0.0D0
837 c           chip1=0.0D0
838 c           chip2=0.0D0
839 c           chip12=0.0D0
840 c           alf1=0.0D0
841 c           alf2=0.0D0
842 c           alf12=0.0D0
843             xj=c(1,nres+j)-xi
844             yj=c(2,nres+j)-yi
845             zj=c(3,nres+j)-zi
846             dxj=dc_norm(1,nres+j)
847             dyj=dc_norm(2,nres+j)
848             dzj=dc_norm(3,nres+j)
849 c            write (iout,*) i,j,xj,yj,zj
850             rrij=1.0D0/(xj*xj+yj*yj+zj*zj)
851             rij=dsqrt(rrij)
852 C Calculate angle-dependent terms of energy and contributions to their
853 C derivatives.
854             call sc_angular
855             sigsq=1.0D0/sigsq
856             sig=sig0ij*dsqrt(sigsq)
857             rij_shift=1.0D0/rij-sig+sig0ij
858 C I hate to put IF's in the loops, but here don't have another choice!!!!
859             if (rij_shift.le.0.0D0) then
860               evdw=1.0D20
861               return
862             endif
863             sigder=-sig*sigsq
864 c---------------------------------------------------------------
865             rij_shift=1.0D0/rij_shift 
866             fac=rij_shift**expon
867             e1=fac*fac*aa(itypi,itypj)
868             e2=fac*bb(itypi,itypj)
869             evdwij=eps1*eps2rt*eps3rt*(e1+e2)
870             eps2der=evdwij*eps3rt
871             eps3der=evdwij*eps2rt
872             evdwij=evdwij*eps2rt*eps3rt
873             if (bb(itypi,itypj).gt.0) then
874               evdw=evdw+evdwij
875             else
876               evdw_t=evdw_t+evdwij
877             endif
878             ij=icant(itypi,itypj)
879             aux=eps1*eps2rt**2*eps3rt**2
880             eneps_temp(1,ij)=eneps_temp(1,ij)+aux*e1
881      &        /dabs(eps(itypi,itypj))
882             eneps_temp(2,ij)=eneps_temp(2,ij)+aux*e2/eps(itypi,itypj)
883 c            write (iout,*) "i",i," j",j," itypi",itypi," itypj",itypj,
884 c     &         " ij",ij," eneps",aux*e1/dabs(eps(itypi,itypj)),
885 c     &         aux*e2/eps(itypi,itypj)
886 c       write (iout,'(a6,2i5,0pf7.3)') 'evdw',i,j,evdwij
887             if (lprn) then
888             sigm=dabs(aa(itypi,itypj)/bb(itypi,itypj))**(1.0D0/6.0D0)
889             epsi=bb(itypi,itypj)**2/aa(itypi,itypj)
890             write (iout,'(2(a3,i3,2x),17(0pf7.3))')
891      &        restyp(itypi),i,restyp(itypj),j,
892      &        epsi,sigm,chi1,chi2,chip1,chip2,
893      &        eps1,eps2rt**2,eps3rt**2,sig,sig0ij,
894      &        om1,om2,om12,1.0D0/rij,1.0D0/rij_shift,
895      &        evdwij
896             endif
897             if (calc_grad) then
898 C Calculate gradient components.
899             e1=e1*eps1*eps2rt**2*eps3rt**2
900             fac=-expon*(e1+evdwij)*rij_shift
901             sigder=fac*sigder
902             fac=rij*fac
903 C Calculate the radial part of the gradient
904             gg(1)=xj*fac
905             gg(2)=yj*fac
906             gg(3)=zj*fac
907 C Calculate angular part of the gradient.
908             call sc_grad
909             endif
910             ENDIF    ! dyn_ss
911           enddo      ! j
912         enddo        ! iint
913       enddo          ! i
914       return
915       end
916 C-----------------------------------------------------------------------------
917       subroutine egbv(evdw,evdw_t)
918 C
919 C This subroutine calculates the interaction energy of nonbonded side chains
920 C assuming the Gay-Berne-Vorobjev potential of interaction.
921 C
922       implicit real*8 (a-h,o-z)
923       include 'DIMENSIONS'
924       include 'DIMENSIONS.ZSCOPT'
925       include "DIMENSIONS.COMPAR"
926       include 'COMMON.GEO'
927       include 'COMMON.VAR'
928       include 'COMMON.LOCAL'
929       include 'COMMON.CHAIN'
930       include 'COMMON.DERIV'
931       include 'COMMON.NAMES'
932       include 'COMMON.INTERACT'
933       include 'COMMON.ENEPS'
934       include 'COMMON.IOUNITS'
935       include 'COMMON.CALC'
936       common /srutu/ icall
937       logical lprn
938       integer icant
939       external icant
940       do i=1,210
941         do j=1,2
942           eneps_temp(j,i)=0.0d0
943         enddo
944       enddo
945       evdw=0.0D0
946       evdw_t=0.0d0
947 c     print *,'Entering EGB nnt=',nnt,' nct=',nct,' expon=',expon
948       evdw=0.0D0
949       lprn=.false.
950 c      if (icall.gt.0) lprn=.true.
951       ind=0
952       do i=iatsc_s,iatsc_e
953         itypi=itype(i)
954         itypi1=itype(i+1)
955         xi=c(1,nres+i)
956         yi=c(2,nres+i)
957         zi=c(3,nres+i)
958         dxi=dc_norm(1,nres+i)
959         dyi=dc_norm(2,nres+i)
960         dzi=dc_norm(3,nres+i)
961         dsci_inv=vbld_inv(i+nres)
962 C
963 C Calculate SC interaction energy.
964 C
965         do iint=1,nint_gr(i)
966           do j=istart(i,iint),iend(i,iint)
967             ind=ind+1
968             itypj=itype(j)
969             dscj_inv=vbld_inv(j+nres)
970             sig0ij=sigma(itypi,itypj)
971             r0ij=r0(itypi,itypj)
972             chi1=chi(itypi,itypj)
973             chi2=chi(itypj,itypi)
974             chi12=chi1*chi2
975             chip1=chip(itypi)
976             chip2=chip(itypj)
977             chip12=chip1*chip2
978             alf1=alp(itypi)
979             alf2=alp(itypj)
980             alf12=0.5D0*(alf1+alf2)
981 C For diagnostics only!!!
982 c           chi1=0.0D0
983 c           chi2=0.0D0
984 c           chi12=0.0D0
985 c           chip1=0.0D0
986 c           chip2=0.0D0
987 c           chip12=0.0D0
988 c           alf1=0.0D0
989 c           alf2=0.0D0
990 c           alf12=0.0D0
991             xj=c(1,nres+j)-xi
992             yj=c(2,nres+j)-yi
993             zj=c(3,nres+j)-zi
994             dxj=dc_norm(1,nres+j)
995             dyj=dc_norm(2,nres+j)
996             dzj=dc_norm(3,nres+j)
997             rrij=1.0D0/(xj*xj+yj*yj+zj*zj)
998             rij=dsqrt(rrij)
999 C Calculate angle-dependent terms of energy and contributions to their
1000 C derivatives.
1001             call sc_angular
1002             sigsq=1.0D0/sigsq
1003             sig=sig0ij*dsqrt(sigsq)
1004             rij_shift=1.0D0/rij-sig+r0ij
1005 C I hate to put IF's in the loops, but here don't have another choice!!!!
1006             if (rij_shift.le.0.0D0) then
1007               evdw=1.0D20
1008               return
1009             endif
1010             sigder=-sig*sigsq
1011 c---------------------------------------------------------------
1012             rij_shift=1.0D0/rij_shift 
1013             fac=rij_shift**expon
1014             e1=fac*fac*aa(itypi,itypj)
1015             e2=fac*bb(itypi,itypj)
1016             evdwij=eps1*eps2rt*eps3rt*(e1+e2)
1017             eps2der=evdwij*eps3rt
1018             eps3der=evdwij*eps2rt
1019             fac_augm=rrij**expon
1020             e_augm=augm(itypi,itypj)*fac_augm
1021             evdwij=evdwij*eps2rt*eps3rt
1022             if (bb(itypi,itypj).gt.0.0d0) then
1023               evdw=evdw+evdwij+e_augm
1024             else
1025               evdw_t=evdw_t+evdwij+e_augm
1026             endif
1027             ij=icant(itypi,itypj)
1028             aux=eps1*eps2rt**2*eps3rt**2
1029             eneps_temp(1,ij)=eneps_temp(1,ij)+aux*(e1+e_augm)
1030      &        /dabs(eps(itypi,itypj))
1031             eneps_temp(2,ij)=eneps_temp(2,ij)+aux*e2/eps(itypi,itypj)
1032 c            eneps_temp(ij)=eneps_temp(ij)
1033 c     &         +(evdwij+e_augm)/eps(itypi,itypj)
1034 c            if (lprn) then
1035 c            sigm=dabs(aa(itypi,itypj)/bb(itypi,itypj))**(1.0D0/6.0D0)
1036 c            epsi=bb(itypi,itypj)**2/aa(itypi,itypj)
1037 c            write (iout,'(2(a3,i3,2x),17(0pf7.3))')
1038 c     &        restyp(itypi),i,restyp(itypj),j,
1039 c     &        epsi,sigm,sig,(augm(itypi,itypj)/epsi)**(1.0D0/12.0D0),
1040 c     &        chi1,chi2,chip1,chip2,
1041 c     &        eps1,eps2rt**2,eps3rt**2,
1042 c     &        om1,om2,om12,1.0D0/rij,1.0D0/rij_shift,
1043 c     &        evdwij+e_augm
1044 c            endif
1045             if (calc_grad) then
1046 C Calculate gradient components.
1047             e1=e1*eps1*eps2rt**2*eps3rt**2
1048             fac=-expon*(e1+evdwij)*rij_shift
1049             sigder=fac*sigder
1050             fac=rij*fac-2*expon*rrij*e_augm
1051 C Calculate the radial part of the gradient
1052             gg(1)=xj*fac
1053             gg(2)=yj*fac
1054             gg(3)=zj*fac
1055 C Calculate angular part of the gradient.
1056             call sc_grad
1057             endif
1058           enddo      ! j
1059         enddo        ! iint
1060       enddo          ! i
1061       return
1062       end
1063 C-----------------------------------------------------------------------------
1064       subroutine sc_angular
1065 C Calculate eps1,eps2,eps3,sigma, and parts of their derivatives in om1,om2,
1066 C om12. Called by ebp, egb, and egbv.
1067       implicit none
1068       include 'COMMON.CALC'
1069       erij(1)=xj*rij
1070       erij(2)=yj*rij
1071       erij(3)=zj*rij
1072       om1=dxi*erij(1)+dyi*erij(2)+dzi*erij(3)
1073       om2=dxj*erij(1)+dyj*erij(2)+dzj*erij(3)
1074       om12=dxi*dxj+dyi*dyj+dzi*dzj
1075       chiom12=chi12*om12
1076 C Calculate eps1(om12) and its derivative in om12
1077       faceps1=1.0D0-om12*chiom12
1078       faceps1_inv=1.0D0/faceps1
1079       eps1=dsqrt(faceps1_inv)
1080 C Following variable is eps1*deps1/dom12
1081       eps1_om12=faceps1_inv*chiom12
1082 C Calculate sigma(om1,om2,om12) and the derivatives of sigma**2 in om1,om2,
1083 C and om12.
1084       om1om2=om1*om2
1085       chiom1=chi1*om1
1086       chiom2=chi2*om2
1087       facsig=om1*chiom1+om2*chiom2-2.0D0*om1om2*chiom12
1088       sigsq=1.0D0-facsig*faceps1_inv
1089       sigsq_om1=(chiom1-chiom12*om2)*faceps1_inv
1090       sigsq_om2=(chiom2-chiom12*om1)*faceps1_inv
1091       sigsq_om12=-chi12*(om1om2*faceps1-om12*facsig)*faceps1_inv**2
1092 C Calculate eps2 and its derivatives in om1, om2, and om12.
1093       chipom1=chip1*om1
1094       chipom2=chip2*om2
1095       chipom12=chip12*om12
1096       facp=1.0D0-om12*chipom12
1097       facp_inv=1.0D0/facp
1098       facp1=om1*chipom1+om2*chipom2-2.0D0*om1om2*chipom12
1099 C Following variable is the square root of eps2
1100       eps2rt=1.0D0-facp1*facp_inv
1101 C Following three variables are the derivatives of the square root of eps
1102 C in om1, om2, and om12.
1103       eps2rt_om1=-4.0D0*(chipom1-chipom12*om2)*facp_inv
1104       eps2rt_om2=-4.0D0*(chipom2-chipom12*om1)*facp_inv
1105       eps2rt_om12=4.0D0*chip12*(om1om2*facp-om12*facp1)*facp_inv**2 
1106 C Evaluate the "asymmetric" factor in the VDW constant, eps3
1107       eps3rt=1.0D0-alf1*om1+alf2*om2-alf12*om12 
1108 C Calculate whole angle-dependent part of epsilon and contributions
1109 C to its derivatives
1110       return
1111       end
1112 C----------------------------------------------------------------------------
1113       subroutine sc_grad
1114       implicit real*8 (a-h,o-z)
1115       include 'DIMENSIONS'
1116       include 'DIMENSIONS.ZSCOPT'
1117       include 'COMMON.CHAIN'
1118       include 'COMMON.DERIV'
1119       include 'COMMON.CALC'
1120       double precision dcosom1(3),dcosom2(3)
1121       eom1=eps2der*eps2rt_om1-2.0D0*alf1*eps3der+sigder*sigsq_om1
1122       eom2=eps2der*eps2rt_om2+2.0D0*alf2*eps3der+sigder*sigsq_om2
1123       eom12=evdwij*eps1_om12+eps2der*eps2rt_om12
1124      &     -2.0D0*alf12*eps3der+sigder*sigsq_om12
1125       do k=1,3
1126         dcosom1(k)=rij*(dc_norm(k,nres+i)-om1*erij(k))
1127         dcosom2(k)=rij*(dc_norm(k,nres+j)-om2*erij(k))
1128       enddo
1129       do k=1,3
1130         gg(k)=gg(k)+eom1*dcosom1(k)+eom2*dcosom2(k)
1131       enddo 
1132       do k=1,3
1133         gvdwx(k,i)=gvdwx(k,i)-gg(k)
1134      &            +(eom12*(dc_norm(k,nres+j)-om12*dc_norm(k,nres+i))
1135      &            +eom1*(erij(k)-om1*dc_norm(k,nres+i)))*dsci_inv
1136         gvdwx(k,j)=gvdwx(k,j)+gg(k)
1137      &            +(eom12*(dc_norm(k,nres+i)-om12*dc_norm(k,nres+j))
1138      &            +eom2*(erij(k)-om2*dc_norm(k,nres+j)))*dscj_inv
1139       enddo
1140
1141 C Calculate the components of the gradient in DC and X
1142 C
1143       do k=i,j-1
1144         do l=1,3
1145           gvdwc(l,k)=gvdwc(l,k)+gg(l)
1146         enddo
1147       enddo
1148       return
1149       end
1150 c------------------------------------------------------------------------------
1151       subroutine vec_and_deriv
1152       implicit real*8 (a-h,o-z)
1153       include 'DIMENSIONS'
1154       include 'DIMENSIONS.ZSCOPT'
1155       include 'COMMON.IOUNITS'
1156       include 'COMMON.GEO'
1157       include 'COMMON.VAR'
1158       include 'COMMON.LOCAL'
1159       include 'COMMON.CHAIN'
1160       include 'COMMON.VECTORS'
1161       include 'COMMON.DERIV'
1162       include 'COMMON.INTERACT'
1163       dimension uyder(3,3,2),uzder(3,3,2),vbld_inv_temp(2)
1164 C Compute the local reference systems. For reference system (i), the
1165 C X-axis points from CA(i) to CA(i+1), the Y axis is in the 
1166 C CA(i)-CA(i+1)-CA(i+2) plane, and the Z axis is perpendicular to this plane.
1167       do i=1,nres-1
1168 c          if (i.eq.nres-1 .or. itel(i+1).eq.0) then
1169           if (i.eq.nres-1) then
1170 C Case of the last full residue
1171 C Compute the Z-axis
1172             call vecpr(dc_norm(1,i),dc_norm(1,i-1),uz(1,i))
1173             costh=dcos(pi-theta(nres))
1174             fac=1.0d0/dsqrt(1.0d0-costh*costh)
1175             do k=1,3
1176               uz(k,i)=fac*uz(k,i)
1177             enddo
1178             if (calc_grad) then
1179 C Compute the derivatives of uz
1180             uzder(1,1,1)= 0.0d0
1181             uzder(2,1,1)=-dc_norm(3,i-1)
1182             uzder(3,1,1)= dc_norm(2,i-1) 
1183             uzder(1,2,1)= dc_norm(3,i-1)
1184             uzder(2,2,1)= 0.0d0
1185             uzder(3,2,1)=-dc_norm(1,i-1)
1186             uzder(1,3,1)=-dc_norm(2,i-1)
1187             uzder(2,3,1)= dc_norm(1,i-1)
1188             uzder(3,3,1)= 0.0d0
1189             uzder(1,1,2)= 0.0d0
1190             uzder(2,1,2)= dc_norm(3,i)
1191             uzder(3,1,2)=-dc_norm(2,i) 
1192             uzder(1,2,2)=-dc_norm(3,i)
1193             uzder(2,2,2)= 0.0d0
1194             uzder(3,2,2)= dc_norm(1,i)
1195             uzder(1,3,2)= dc_norm(2,i)
1196             uzder(2,3,2)=-dc_norm(1,i)
1197             uzder(3,3,2)= 0.0d0
1198             endif
1199 C Compute the Y-axis
1200             facy=fac
1201             do k=1,3
1202               uy(k,i)=fac*(dc_norm(k,i-1)-costh*dc_norm(k,i))
1203             enddo
1204             if (calc_grad) then
1205 C Compute the derivatives of uy
1206             do j=1,3
1207               do k=1,3
1208                 uyder(k,j,1)=2*dc_norm(k,i-1)*dc_norm(j,i)
1209      &                        -dc_norm(k,i)*dc_norm(j,i-1)
1210                 uyder(k,j,2)=-dc_norm(j,i)*dc_norm(k,i)
1211               enddo
1212               uyder(j,j,1)=uyder(j,j,1)-costh
1213               uyder(j,j,2)=1.0d0+uyder(j,j,2)
1214             enddo
1215             do j=1,2
1216               do k=1,3
1217                 do l=1,3
1218                   uygrad(l,k,j,i)=uyder(l,k,j)
1219                   uzgrad(l,k,j,i)=uzder(l,k,j)
1220                 enddo
1221               enddo
1222             enddo 
1223             call unormderiv(uy(1,i),uyder(1,1,1),facy,uygrad(1,1,1,i))
1224             call unormderiv(uy(1,i),uyder(1,1,2),facy,uygrad(1,1,2,i))
1225             call unormderiv(uz(1,i),uzder(1,1,1),fac,uzgrad(1,1,1,i))
1226             call unormderiv(uz(1,i),uzder(1,1,2),fac,uzgrad(1,1,2,i))
1227             endif
1228           else
1229 C Other residues
1230 C Compute the Z-axis
1231             call vecpr(dc_norm(1,i),dc_norm(1,i+1),uz(1,i))
1232             costh=dcos(pi-theta(i+2))
1233             fac=1.0d0/dsqrt(1.0d0-costh*costh)
1234             do k=1,3
1235               uz(k,i)=fac*uz(k,i)
1236             enddo
1237             if (calc_grad) then
1238 C Compute the derivatives of uz
1239             uzder(1,1,1)= 0.0d0
1240             uzder(2,1,1)=-dc_norm(3,i+1)
1241             uzder(3,1,1)= dc_norm(2,i+1) 
1242             uzder(1,2,1)= dc_norm(3,i+1)
1243             uzder(2,2,1)= 0.0d0
1244             uzder(3,2,1)=-dc_norm(1,i+1)
1245             uzder(1,3,1)=-dc_norm(2,i+1)
1246             uzder(2,3,1)= dc_norm(1,i+1)
1247             uzder(3,3,1)= 0.0d0
1248             uzder(1,1,2)= 0.0d0
1249             uzder(2,1,2)= dc_norm(3,i)
1250             uzder(3,1,2)=-dc_norm(2,i) 
1251             uzder(1,2,2)=-dc_norm(3,i)
1252             uzder(2,2,2)= 0.0d0
1253             uzder(3,2,2)= dc_norm(1,i)
1254             uzder(1,3,2)= dc_norm(2,i)
1255             uzder(2,3,2)=-dc_norm(1,i)
1256             uzder(3,3,2)= 0.0d0
1257             endif
1258 C Compute the Y-axis
1259             facy=fac
1260             do k=1,3
1261               uy(k,i)=facy*(dc_norm(k,i+1)-costh*dc_norm(k,i))
1262             enddo
1263             if (calc_grad) then
1264 C Compute the derivatives of uy
1265             do j=1,3
1266               do k=1,3
1267                 uyder(k,j,1)=2*dc_norm(k,i+1)*dc_norm(j,i)
1268      &                        -dc_norm(k,i)*dc_norm(j,i+1)
1269                 uyder(k,j,2)=-dc_norm(j,i)*dc_norm(k,i)
1270               enddo
1271               uyder(j,j,1)=uyder(j,j,1)-costh
1272               uyder(j,j,2)=1.0d0+uyder(j,j,2)
1273             enddo
1274             do j=1,2
1275               do k=1,3
1276                 do l=1,3
1277                   uygrad(l,k,j,i)=uyder(l,k,j)
1278                   uzgrad(l,k,j,i)=uzder(l,k,j)
1279                 enddo
1280               enddo
1281             enddo 
1282             call unormderiv(uy(1,i),uyder(1,1,1),facy,uygrad(1,1,1,i))
1283             call unormderiv(uy(1,i),uyder(1,1,2),facy,uygrad(1,1,2,i))
1284             call unormderiv(uz(1,i),uzder(1,1,1),fac,uzgrad(1,1,1,i))
1285             call unormderiv(uz(1,i),uzder(1,1,2),fac,uzgrad(1,1,2,i))
1286           endif
1287           endif
1288       enddo
1289       if (calc_grad) then
1290       do i=1,nres-1
1291         vbld_inv_temp(1)=vbld_inv(i+1)
1292         if (i.lt.nres-1) then
1293           vbld_inv_temp(2)=vbld_inv(i+2)
1294         else
1295           vbld_inv_temp(2)=vbld_inv(i)
1296         endif
1297         do j=1,2
1298           do k=1,3
1299             do l=1,3
1300               uygrad(l,k,j,i)=vbld_inv_temp(j)*uygrad(l,k,j,i)
1301               uzgrad(l,k,j,i)=vbld_inv_temp(j)*uzgrad(l,k,j,i)
1302             enddo
1303           enddo
1304         enddo
1305       enddo
1306       endif
1307       return
1308       end
1309 C-----------------------------------------------------------------------------
1310       subroutine vec_and_deriv_test
1311       implicit real*8 (a-h,o-z)
1312       include 'DIMENSIONS'
1313       include 'DIMENSIONS.ZSCOPT'
1314       include 'COMMON.IOUNITS'
1315       include 'COMMON.GEO'
1316       include 'COMMON.VAR'
1317       include 'COMMON.LOCAL'
1318       include 'COMMON.CHAIN'
1319       include 'COMMON.VECTORS'
1320       dimension uyder(3,3,2),uzder(3,3,2)
1321 C Compute the local reference systems. For reference system (i), the
1322 C X-axis points from CA(i) to CA(i+1), the Y axis is in the 
1323 C CA(i)-CA(i+1)-CA(i+2) plane, and the Z axis is perpendicular to this plane.
1324       do i=1,nres-1
1325           if (i.eq.nres-1) then
1326 C Case of the last full residue
1327 C Compute the Z-axis
1328             call vecpr(dc_norm(1,i),dc_norm(1,i-1),uz(1,i))
1329             costh=dcos(pi-theta(nres))
1330             fac=1.0d0/dsqrt(1.0d0-costh*costh)
1331 c            write (iout,*) 'fac',fac,
1332 c     &        1.0d0/dsqrt(scalar(uz(1,i),uz(1,i)))
1333             fac=1.0d0/dsqrt(scalar(uz(1,i),uz(1,i)))
1334             do k=1,3
1335               uz(k,i)=fac*uz(k,i)
1336             enddo
1337 C Compute the derivatives of uz
1338             uzder(1,1,1)= 0.0d0
1339             uzder(2,1,1)=-dc_norm(3,i-1)
1340             uzder(3,1,1)= dc_norm(2,i-1) 
1341             uzder(1,2,1)= dc_norm(3,i-1)
1342             uzder(2,2,1)= 0.0d0
1343             uzder(3,2,1)=-dc_norm(1,i-1)
1344             uzder(1,3,1)=-dc_norm(2,i-1)
1345             uzder(2,3,1)= dc_norm(1,i-1)
1346             uzder(3,3,1)= 0.0d0
1347             uzder(1,1,2)= 0.0d0
1348             uzder(2,1,2)= dc_norm(3,i)
1349             uzder(3,1,2)=-dc_norm(2,i) 
1350             uzder(1,2,2)=-dc_norm(3,i)
1351             uzder(2,2,2)= 0.0d0
1352             uzder(3,2,2)= dc_norm(1,i)
1353             uzder(1,3,2)= dc_norm(2,i)
1354             uzder(2,3,2)=-dc_norm(1,i)
1355             uzder(3,3,2)= 0.0d0
1356 C Compute the Y-axis
1357             do k=1,3
1358               uy(k,i)=fac*(dc_norm(k,i-1)-costh*dc_norm(k,i))
1359             enddo
1360             facy=fac
1361             facy=1.0d0/dsqrt(scalar(dc_norm(1,i),dc_norm(1,i))*
1362      &       (scalar(dc_norm(1,i-1),dc_norm(1,i-1))**2-
1363      &        scalar(dc_norm(1,i),dc_norm(1,i-1))**2))
1364             do k=1,3
1365 c              uy(k,i)=facy*(dc_norm(k,i+1)-costh*dc_norm(k,i))
1366               uy(k,i)=
1367 c     &        facy*(
1368      &        dc_norm(k,i-1)*scalar(dc_norm(1,i),dc_norm(1,i))
1369      &        -scalar(dc_norm(1,i),dc_norm(1,i-1))*dc_norm(k,i)
1370 c     &        )
1371             enddo
1372 c            write (iout,*) 'facy',facy,
1373 c     &       1.0d0/dsqrt(scalar(uy(1,i),uy(1,i)))
1374             facy=1.0d0/dsqrt(scalar(uy(1,i),uy(1,i)))
1375             do k=1,3
1376               uy(k,i)=facy*uy(k,i)
1377             enddo
1378 C Compute the derivatives of uy
1379             do j=1,3
1380               do k=1,3
1381                 uyder(k,j,1)=2*dc_norm(k,i-1)*dc_norm(j,i)
1382      &                        -dc_norm(k,i)*dc_norm(j,i-1)
1383                 uyder(k,j,2)=-dc_norm(j,i)*dc_norm(k,i)
1384               enddo
1385 c              uyder(j,j,1)=uyder(j,j,1)-costh
1386 c              uyder(j,j,2)=1.0d0+uyder(j,j,2)
1387               uyder(j,j,1)=uyder(j,j,1)
1388      &          -scalar(dc_norm(1,i),dc_norm(1,i-1))
1389               uyder(j,j,2)=scalar(dc_norm(1,i),dc_norm(1,i))
1390      &          +uyder(j,j,2)
1391             enddo
1392             do j=1,2
1393               do k=1,3
1394                 do l=1,3
1395                   uygrad(l,k,j,i)=uyder(l,k,j)
1396                   uzgrad(l,k,j,i)=uzder(l,k,j)
1397                 enddo
1398               enddo
1399             enddo 
1400             call unormderiv(uy(1,i),uyder(1,1,1),facy,uygrad(1,1,1,i))
1401             call unormderiv(uy(1,i),uyder(1,1,2),facy,uygrad(1,1,2,i))
1402             call unormderiv(uz(1,i),uzder(1,1,1),fac,uzgrad(1,1,1,i))
1403             call unormderiv(uz(1,i),uzder(1,1,2),fac,uzgrad(1,1,2,i))
1404           else
1405 C Other residues
1406 C Compute the Z-axis
1407             call vecpr(dc_norm(1,i),dc_norm(1,i+1),uz(1,i))
1408             costh=dcos(pi-theta(i+2))
1409             fac=1.0d0/dsqrt(1.0d0-costh*costh)
1410             fac=1.0d0/dsqrt(scalar(uz(1,i),uz(1,i)))
1411             do k=1,3
1412               uz(k,i)=fac*uz(k,i)
1413             enddo
1414 C Compute the derivatives of uz
1415             uzder(1,1,1)= 0.0d0
1416             uzder(2,1,1)=-dc_norm(3,i+1)
1417             uzder(3,1,1)= dc_norm(2,i+1) 
1418             uzder(1,2,1)= dc_norm(3,i+1)
1419             uzder(2,2,1)= 0.0d0
1420             uzder(3,2,1)=-dc_norm(1,i+1)
1421             uzder(1,3,1)=-dc_norm(2,i+1)
1422             uzder(2,3,1)= dc_norm(1,i+1)
1423             uzder(3,3,1)= 0.0d0
1424             uzder(1,1,2)= 0.0d0
1425             uzder(2,1,2)= dc_norm(3,i)
1426             uzder(3,1,2)=-dc_norm(2,i) 
1427             uzder(1,2,2)=-dc_norm(3,i)
1428             uzder(2,2,2)= 0.0d0
1429             uzder(3,2,2)= dc_norm(1,i)
1430             uzder(1,3,2)= dc_norm(2,i)
1431             uzder(2,3,2)=-dc_norm(1,i)
1432             uzder(3,3,2)= 0.0d0
1433 C Compute the Y-axis
1434             facy=fac
1435             facy=1.0d0/dsqrt(scalar(dc_norm(1,i),dc_norm(1,i))*
1436      &       (scalar(dc_norm(1,i+1),dc_norm(1,i+1))**2-
1437      &        scalar(dc_norm(1,i),dc_norm(1,i+1))**2))
1438             do k=1,3
1439 c              uy(k,i)=facy*(dc_norm(k,i+1)-costh*dc_norm(k,i))
1440               uy(k,i)=
1441 c     &        facy*(
1442      &        dc_norm(k,i+1)*scalar(dc_norm(1,i),dc_norm(1,i))
1443      &        -scalar(dc_norm(1,i),dc_norm(1,i+1))*dc_norm(k,i)
1444 c     &        )
1445             enddo
1446 c            write (iout,*) 'facy',facy,
1447 c     &       1.0d0/dsqrt(scalar(uy(1,i),uy(1,i)))
1448             facy=1.0d0/dsqrt(scalar(uy(1,i),uy(1,i)))
1449             do k=1,3
1450               uy(k,i)=facy*uy(k,i)
1451             enddo
1452 C Compute the derivatives of uy
1453             do j=1,3
1454               do k=1,3
1455                 uyder(k,j,1)=2*dc_norm(k,i+1)*dc_norm(j,i)
1456      &                        -dc_norm(k,i)*dc_norm(j,i+1)
1457                 uyder(k,j,2)=-dc_norm(j,i)*dc_norm(k,i)
1458               enddo
1459 c              uyder(j,j,1)=uyder(j,j,1)-costh
1460 c              uyder(j,j,2)=1.0d0+uyder(j,j,2)
1461               uyder(j,j,1)=uyder(j,j,1)
1462      &          -scalar(dc_norm(1,i),dc_norm(1,i+1))
1463               uyder(j,j,2)=scalar(dc_norm(1,i),dc_norm(1,i))
1464      &          +uyder(j,j,2)
1465             enddo
1466             do j=1,2
1467               do k=1,3
1468                 do l=1,3
1469                   uygrad(l,k,j,i)=uyder(l,k,j)
1470                   uzgrad(l,k,j,i)=uzder(l,k,j)
1471                 enddo
1472               enddo
1473             enddo 
1474             call unormderiv(uy(1,i),uyder(1,1,1),facy,uygrad(1,1,1,i))
1475             call unormderiv(uy(1,i),uyder(1,1,2),facy,uygrad(1,1,2,i))
1476             call unormderiv(uz(1,i),uzder(1,1,1),fac,uzgrad(1,1,1,i))
1477             call unormderiv(uz(1,i),uzder(1,1,2),fac,uzgrad(1,1,2,i))
1478           endif
1479       enddo
1480       do i=1,nres-1
1481         do j=1,2
1482           do k=1,3
1483             do l=1,3
1484               uygrad(l,k,j,i)=vblinv*uygrad(l,k,j,i)
1485               uzgrad(l,k,j,i)=vblinv*uzgrad(l,k,j,i)
1486             enddo
1487           enddo
1488         enddo
1489       enddo
1490       return
1491       end
1492 C-----------------------------------------------------------------------------
1493       subroutine check_vecgrad
1494       implicit real*8 (a-h,o-z)
1495       include 'DIMENSIONS'
1496       include 'DIMENSIONS.ZSCOPT'
1497       include 'COMMON.IOUNITS'
1498       include 'COMMON.GEO'
1499       include 'COMMON.VAR'
1500       include 'COMMON.LOCAL'
1501       include 'COMMON.CHAIN'
1502       include 'COMMON.VECTORS'
1503       dimension uygradt(3,3,2,maxres),uzgradt(3,3,2,maxres)
1504       dimension uyt(3,maxres),uzt(3,maxres)
1505       dimension uygradn(3,3,2),uzgradn(3,3,2),erij(3)
1506       double precision delta /1.0d-7/
1507       call vec_and_deriv
1508 cd      do i=1,nres
1509 crc          write(iout,'(2i5,2(3f10.5,5x))') i,1,dc_norm(:,i)
1510 crc          write(iout,'(2i5,2(3f10.5,5x))') i,2,uy(:,i)
1511 crc          write(iout,'(2i5,2(3f10.5,5x)/)')i,3,uz(:,i)
1512 cd          write(iout,'(2i5,2(3f10.5,5x))') i,1,
1513 cd     &     (dc_norm(if90,i),if90=1,3)
1514 cd          write(iout,'(2i5,2(3f10.5,5x))') i,2,(uy(if90,i),if90=1,3)
1515 cd          write(iout,'(2i5,2(3f10.5,5x)/)')i,3,(uz(if90,i),if90=1,3)
1516 cd          write(iout,'(a)')
1517 cd      enddo
1518       do i=1,nres
1519         do j=1,2
1520           do k=1,3
1521             do l=1,3
1522               uygradt(l,k,j,i)=uygrad(l,k,j,i)
1523               uzgradt(l,k,j,i)=uzgrad(l,k,j,i)
1524             enddo
1525           enddo
1526         enddo
1527       enddo
1528       call vec_and_deriv
1529       do i=1,nres
1530         do j=1,3
1531           uyt(j,i)=uy(j,i)
1532           uzt(j,i)=uz(j,i)
1533         enddo
1534       enddo
1535       do i=1,nres
1536 cd        write (iout,*) 'i=',i
1537         do k=1,3
1538           erij(k)=dc_norm(k,i)
1539         enddo
1540         do j=1,3
1541           do k=1,3
1542             dc_norm(k,i)=erij(k)
1543           enddo
1544           dc_norm(j,i)=dc_norm(j,i)+delta
1545 c          fac=dsqrt(scalar(dc_norm(1,i),dc_norm(1,i)))
1546 c          do k=1,3
1547 c            dc_norm(k,i)=dc_norm(k,i)/fac
1548 c          enddo
1549 c          write (iout,*) (dc_norm(k,i),k=1,3)
1550 c          write (iout,*) (erij(k),k=1,3)
1551           call vec_and_deriv
1552           do k=1,3
1553             uygradn(k,j,1)=(uy(k,i)-uyt(k,i))/delta
1554             uygradn(k,j,2)=(uy(k,i-1)-uyt(k,i-1))/delta
1555             uzgradn(k,j,1)=(uz(k,i)-uzt(k,i))/delta
1556             uzgradn(k,j,2)=(uz(k,i-1)-uzt(k,i-1))/delta
1557           enddo 
1558 c          write (iout,'(i5,3f8.5,3x,3f8.5,5x,3f8.5,3x,3f8.5)') 
1559 c     &      j,(uzgradt(k,j,1,i),k=1,3),(uzgradn(k,j,1),k=1,3),
1560 c     &      (uzgradt(k,j,2,i-1),k=1,3),(uzgradn(k,j,2),k=1,3)
1561         enddo
1562         do k=1,3
1563           dc_norm(k,i)=erij(k)
1564         enddo
1565 cd        do k=1,3
1566 cd          write (iout,'(i5,3f8.5,3x,3f8.5,5x,3f8.5,3x,3f8.5)') 
1567 cd     &      k,(uygradt(k,l,1,i),l=1,3),(uygradn(k,l,1),l=1,3),
1568 cd     &      (uygradt(k,l,2,i-1),l=1,3),(uygradn(k,l,2),l=1,3)
1569 cd          write (iout,'(i5,3f8.5,3x,3f8.5,5x,3f8.5,3x,3f8.5)') 
1570 cd     &      k,(uzgradt(k,l,1,i),l=1,3),(uzgradn(k,l,1),l=1,3),
1571 cd     &      (uzgradt(k,l,2,i-1),l=1,3),(uzgradn(k,l,2),l=1,3)
1572 cd          write (iout,'(a)')
1573 cd        enddo
1574       enddo
1575       return
1576       end
1577 C--------------------------------------------------------------------------
1578       subroutine set_matrices
1579       implicit real*8 (a-h,o-z)
1580       include 'DIMENSIONS'
1581       include 'DIMENSIONS.ZSCOPT'
1582       include 'COMMON.IOUNITS'
1583       include 'COMMON.GEO'
1584       include 'COMMON.VAR'
1585       include 'COMMON.LOCAL'
1586       include 'COMMON.CHAIN'
1587       include 'COMMON.DERIV'
1588       include 'COMMON.INTERACT'
1589       include 'COMMON.CONTACTS'
1590       include 'COMMON.TORSION'
1591       include 'COMMON.VECTORS'
1592       include 'COMMON.FFIELD'
1593       double precision auxvec(2),auxmat(2,2)
1594 C
1595 C Compute the virtual-bond-torsional-angle dependent quantities needed
1596 C to calculate the el-loc multibody terms of various order.
1597 C
1598       do i=3,nres+1
1599         if (i .lt. nres+1) then
1600           sin1=dsin(phi(i))
1601           cos1=dcos(phi(i))
1602           sintab(i-2)=sin1
1603           costab(i-2)=cos1
1604           obrot(1,i-2)=cos1
1605           obrot(2,i-2)=sin1
1606           sin2=dsin(2*phi(i))
1607           cos2=dcos(2*phi(i))
1608           sintab2(i-2)=sin2
1609           costab2(i-2)=cos2
1610           obrot2(1,i-2)=cos2
1611           obrot2(2,i-2)=sin2
1612           Ug(1,1,i-2)=-cos1
1613           Ug(1,2,i-2)=-sin1
1614           Ug(2,1,i-2)=-sin1
1615           Ug(2,2,i-2)= cos1
1616           Ug2(1,1,i-2)=-cos2
1617           Ug2(1,2,i-2)=-sin2
1618           Ug2(2,1,i-2)=-sin2
1619           Ug2(2,2,i-2)= cos2
1620         else
1621           costab(i-2)=1.0d0
1622           sintab(i-2)=0.0d0
1623           obrot(1,i-2)=1.0d0
1624           obrot(2,i-2)=0.0d0
1625           obrot2(1,i-2)=0.0d0
1626           obrot2(2,i-2)=0.0d0
1627           Ug(1,1,i-2)=1.0d0
1628           Ug(1,2,i-2)=0.0d0
1629           Ug(2,1,i-2)=0.0d0
1630           Ug(2,2,i-2)=1.0d0
1631           Ug2(1,1,i-2)=0.0d0
1632           Ug2(1,2,i-2)=0.0d0
1633           Ug2(2,1,i-2)=0.0d0
1634           Ug2(2,2,i-2)=0.0d0
1635         endif
1636         if (i .gt. 3 .and. i .lt. nres+1) then
1637           obrot_der(1,i-2)=-sin1
1638           obrot_der(2,i-2)= cos1
1639           Ugder(1,1,i-2)= sin1
1640           Ugder(1,2,i-2)=-cos1
1641           Ugder(2,1,i-2)=-cos1
1642           Ugder(2,2,i-2)=-sin1
1643           dwacos2=cos2+cos2
1644           dwasin2=sin2+sin2
1645           obrot2_der(1,i-2)=-dwasin2
1646           obrot2_der(2,i-2)= dwacos2
1647           Ug2der(1,1,i-2)= dwasin2
1648           Ug2der(1,2,i-2)=-dwacos2
1649           Ug2der(2,1,i-2)=-dwacos2
1650           Ug2der(2,2,i-2)=-dwasin2
1651         else
1652           obrot_der(1,i-2)=0.0d0
1653           obrot_der(2,i-2)=0.0d0
1654           Ugder(1,1,i-2)=0.0d0
1655           Ugder(1,2,i-2)=0.0d0
1656           Ugder(2,1,i-2)=0.0d0
1657           Ugder(2,2,i-2)=0.0d0
1658           obrot2_der(1,i-2)=0.0d0
1659           obrot2_der(2,i-2)=0.0d0
1660           Ug2der(1,1,i-2)=0.0d0
1661           Ug2der(1,2,i-2)=0.0d0
1662           Ug2der(2,1,i-2)=0.0d0
1663           Ug2der(2,2,i-2)=0.0d0
1664         endif
1665         if (i.gt. iatel_s+2 .and. i.lt.iatel_e+5) then
1666           iti = itortyp(itype(i-2))
1667         else
1668           iti=ntortyp+1
1669         endif
1670         if (i.gt. iatel_s+1 .and. i.lt.iatel_e+4) then
1671           iti1 = itortyp(itype(i-1))
1672         else
1673           iti1=ntortyp+1
1674         endif
1675 cd        write (iout,*) '*******i',i,' iti1',iti
1676 cd        write (iout,*) 'b1',b1(:,iti)
1677 cd        write (iout,*) 'b2',b2(:,iti)
1678 cd        write (iout,*) 'Ug',Ug(:,:,i-2)
1679         if (i .gt. iatel_s+2) then
1680           call matvec2(Ug(1,1,i-2),b2(1,iti),Ub2(1,i-2))
1681           call matmat2(EE(1,1,iti),Ug(1,1,i-2),EUg(1,1,i-2))
1682           call matmat2(CC(1,1,iti),Ug(1,1,i-2),CUg(1,1,i-2))
1683           call matmat2(DD(1,1,iti),Ug(1,1,i-2),DUg(1,1,i-2))
1684           call matmat2(Dtilde(1,1,iti),Ug2(1,1,i-2),DtUg2(1,1,i-2))
1685           call matvec2(Ctilde(1,1,iti1),obrot(1,i-2),Ctobr(1,i-2))
1686           call matvec2(Dtilde(1,1,iti),obrot2(1,i-2),Dtobr2(1,i-2))
1687         else
1688           do k=1,2
1689             Ub2(k,i-2)=0.0d0
1690             Ctobr(k,i-2)=0.0d0 
1691             Dtobr2(k,i-2)=0.0d0
1692             do l=1,2
1693               EUg(l,k,i-2)=0.0d0
1694               CUg(l,k,i-2)=0.0d0
1695               DUg(l,k,i-2)=0.0d0
1696               DtUg2(l,k,i-2)=0.0d0
1697             enddo
1698           enddo
1699         endif
1700         call matvec2(Ugder(1,1,i-2),b2(1,iti),Ub2der(1,i-2))
1701         call matmat2(EE(1,1,iti),Ugder(1,1,i-2),EUgder(1,1,i-2))
1702         call matmat2(CC(1,1,iti1),Ugder(1,1,i-2),CUgder(1,1,i-2))
1703         call matmat2(DD(1,1,iti),Ugder(1,1,i-2),DUgder(1,1,i-2))
1704         call matmat2(Dtilde(1,1,iti),Ug2der(1,1,i-2),DtUg2der(1,1,i-2))
1705         call matvec2(Ctilde(1,1,iti1),obrot_der(1,i-2),Ctobrder(1,i-2))
1706         call matvec2(Dtilde(1,1,iti),obrot2_der(1,i-2),Dtobr2der(1,i-2))
1707         do k=1,2
1708           muder(k,i-2)=Ub2der(k,i-2)
1709         enddo
1710         if (i.gt. iatel_s+1 .and. i.lt.iatel_e+4) then
1711           iti1 = itortyp(itype(i-1))
1712         else
1713           iti1=ntortyp+1
1714         endif
1715         do k=1,2
1716           mu(k,i-2)=Ub2(k,i-2)+b1(k,iti1)
1717         enddo
1718 C Vectors and matrices dependent on a single virtual-bond dihedral.
1719         call matvec2(DD(1,1,iti),b1tilde(1,iti1),auxvec(1))
1720         call matvec2(Ug2(1,1,i-2),auxvec(1),Ug2Db1t(1,i-2)) 
1721         call matvec2(Ug2der(1,1,i-2),auxvec(1),Ug2Db1tder(1,i-2)) 
1722         call matvec2(CC(1,1,iti1),Ub2(1,i-2),CUgb2(1,i-2))
1723         call matvec2(CC(1,1,iti1),Ub2der(1,i-2),CUgb2der(1,i-2))
1724         call matmat2(EUg(1,1,i-2),CC(1,1,iti1),EUgC(1,1,i-2))
1725         call matmat2(EUgder(1,1,i-2),CC(1,1,iti1),EUgCder(1,1,i-2))
1726         call matmat2(EUg(1,1,i-2),DD(1,1,iti1),EUgD(1,1,i-2))
1727         call matmat2(EUgder(1,1,i-2),DD(1,1,iti1),EUgDder(1,1,i-2))
1728 cd        write (iout,*) 'i',i,' mu ',(mu(k,i-2),k=1,2),
1729 cd     &  ' mu1',(b1(k,i-2),k=1,2),' mu2',(Ub2(k,i-2),k=1,2)
1730       enddo
1731 C Matrices dependent on two consecutive virtual-bond dihedrals.
1732 C The order of matrices is from left to right.
1733       do i=2,nres-1
1734         call matmat2(DtUg2(1,1,i-1),EUg(1,1,i),DtUg2EUg(1,1,i))
1735         call matmat2(DtUg2der(1,1,i-1),EUg(1,1,i),DtUg2EUgder(1,1,1,i))
1736         call matmat2(DtUg2(1,1,i-1),EUgder(1,1,i),DtUg2EUgder(1,1,2,i))
1737         call transpose2(DtUg2(1,1,i-1),auxmat(1,1))
1738         call matmat2(auxmat(1,1),EUg(1,1,i),Ug2DtEUg(1,1,i))
1739         call matmat2(auxmat(1,1),EUgder(1,1,i),Ug2DtEUgder(1,1,2,i))
1740         call transpose2(DtUg2der(1,1,i-1),auxmat(1,1))
1741         call matmat2(auxmat(1,1),EUg(1,1,i),Ug2DtEUgder(1,1,1,i))
1742       enddo
1743 cd      do i=1,nres
1744 cd        iti = itortyp(itype(i))
1745 cd        write (iout,*) i
1746 cd        do j=1,2
1747 cd        write (iout,'(2f10.5,5x,2f10.5,5x,2f10.5)') 
1748 cd     &  (EE(j,k,iti),k=1,2),(Ug(j,k,i),k=1,2),(EUg(j,k,i),k=1,2)
1749 cd        enddo
1750 cd      enddo
1751       return
1752       end
1753 C--------------------------------------------------------------------------
1754       subroutine eelec(ees,evdw1,eel_loc,eello_turn3,eello_turn4)
1755 C
1756 C This subroutine calculates the average interaction energy and its gradient
1757 C in the virtual-bond vectors between non-adjacent peptide groups, based on 
1758 C the potential described in Liwo et al., Protein Sci., 1993, 2, 1715. 
1759 C The potential depends both on the distance of peptide-group centers and on 
1760 C the orientation of the CA-CA virtual bonds.
1761
1762       implicit real*8 (a-h,o-z)
1763       include 'DIMENSIONS'
1764       include 'DIMENSIONS.ZSCOPT'
1765       include 'COMMON.CONTROL'
1766       include 'COMMON.IOUNITS'
1767       include 'COMMON.GEO'
1768       include 'COMMON.VAR'
1769       include 'COMMON.LOCAL'
1770       include 'COMMON.CHAIN'
1771       include 'COMMON.DERIV'
1772       include 'COMMON.INTERACT'
1773       include 'COMMON.CONTACTS'
1774       include 'COMMON.TORSION'
1775       include 'COMMON.VECTORS'
1776       include 'COMMON.FFIELD'
1777       dimension ggg(3),gggp(3),gggm(3),erij(3),dcosb(3),dcosg(3),
1778      &          erder(3,3),uryg(3,3),urzg(3,3),vryg(3,3),vrzg(3,3)
1779       double precision acipa(2,2),agg(3,4),aggi(3,4),aggi1(3,4),
1780      &    aggj(3,4),aggj1(3,4),a_temp(2,2),muij(4)
1781       common /locel/ a_temp,agg,aggi,aggi1,aggj,aggj1,j1
1782 c 4/26/02 - AL scaling factor for 1,4 repulsive VDW interactions
1783       double precision scal_el /0.5d0/
1784 C 12/13/98 
1785 C 13-go grudnia roku pamietnego... 
1786       double precision unmat(3,3) /1.0d0,0.0d0,0.0d0,
1787      &                   0.0d0,1.0d0,0.0d0,
1788      &                   0.0d0,0.0d0,1.0d0/
1789 cd      write(iout,*) 'In EELEC'
1790 cd      do i=1,nloctyp
1791 cd        write(iout,*) 'Type',i
1792 cd        write(iout,*) 'B1',B1(:,i)
1793 cd        write(iout,*) 'B2',B2(:,i)
1794 cd        write(iout,*) 'CC',CC(:,:,i)
1795 cd        write(iout,*) 'DD',DD(:,:,i)
1796 cd        write(iout,*) 'EE',EE(:,:,i)
1797 cd      enddo
1798 cd      call check_vecgrad
1799 cd      stop
1800       if (icheckgrad.eq.1) then
1801         do i=1,nres-1
1802           fac=1.0d0/dsqrt(scalar(dc(1,i),dc(1,i)))
1803           do k=1,3
1804             dc_norm(k,i)=dc(k,i)*fac
1805           enddo
1806 c          write (iout,*) 'i',i,' fac',fac
1807         enddo
1808       endif
1809       if (wel_loc.gt.0.0d0 .or. wcorr4.gt.0.0d0 .or. wcorr5.gt.0.0d0 
1810      &    .or. wcorr6.gt.0.0d0 .or. wturn3.gt.0.0d0 .or. 
1811      &    wturn4.gt.0.0d0 .or. wturn6.gt.0.0d0) then
1812 cd      if (wel_loc.gt.0.0d0) then
1813         if (icheckgrad.eq.1) then
1814         call vec_and_deriv_test
1815         else
1816         call vec_and_deriv
1817         endif
1818         call set_matrices
1819       endif
1820 cd      do i=1,nres-1
1821 cd        write (iout,*) 'i=',i
1822 cd        do k=1,3
1823 cd          write (iout,'(i5,2f10.5)') k,uy(k,i),uz(k,i)
1824 cd        enddo
1825 cd        do k=1,3
1826 cd          write (iout,'(f10.5,2x,3f10.5,2x,3f10.5)') 
1827 cd     &     uz(k,i),(uzgrad(k,l,1,i),l=1,3),(uzgrad(k,l,2,i),l=1,3)
1828 cd        enddo
1829 cd      enddo
1830       num_conti_hb=0
1831       ees=0.0D0
1832       evdw1=0.0D0
1833       eel_loc=0.0d0 
1834       eello_turn3=0.0d0
1835       eello_turn4=0.0d0
1836       ind=0
1837       do i=1,nres
1838         num_cont_hb(i)=0
1839       enddo
1840 cd      print '(a)','Enter EELEC'
1841 cd      write (iout,*) 'iatel_s=',iatel_s,' iatel_e=',iatel_e
1842       do i=1,nres
1843         gel_loc_loc(i)=0.0d0
1844         gcorr_loc(i)=0.0d0
1845       enddo
1846       do i=iatel_s,iatel_e
1847         if (itel(i).eq.0) goto 1215
1848         dxi=dc(1,i)
1849         dyi=dc(2,i)
1850         dzi=dc(3,i)
1851         dx_normi=dc_norm(1,i)
1852         dy_normi=dc_norm(2,i)
1853         dz_normi=dc_norm(3,i)
1854         xmedi=c(1,i)+0.5d0*dxi
1855         ymedi=c(2,i)+0.5d0*dyi
1856         zmedi=c(3,i)+0.5d0*dzi
1857         num_conti=0
1858 c        write (iout,*) 'i',i,' ielstart',ielstart(i),' ielend',ielend(i)
1859         do j=ielstart(i),ielend(i)
1860           if (itel(j).eq.0) goto 1216
1861           ind=ind+1
1862           iteli=itel(i)
1863           itelj=itel(j)
1864           if (j.eq.i+2 .and. itelj.eq.2) iteli=2
1865           aaa=app(iteli,itelj)
1866           bbb=bpp(iteli,itelj)
1867 C Diagnostics only!!!
1868 c         aaa=0.0D0
1869 c         bbb=0.0D0
1870 c         ael6i=0.0D0
1871 c         ael3i=0.0D0
1872 C End diagnostics
1873           ael6i=ael6(iteli,itelj)
1874           ael3i=ael3(iteli,itelj) 
1875           dxj=dc(1,j)
1876           dyj=dc(2,j)
1877           dzj=dc(3,j)
1878           dx_normj=dc_norm(1,j)
1879           dy_normj=dc_norm(2,j)
1880           dz_normj=dc_norm(3,j)
1881           xj=c(1,j)+0.5D0*dxj-xmedi
1882           yj=c(2,j)+0.5D0*dyj-ymedi
1883           zj=c(3,j)+0.5D0*dzj-zmedi
1884           rij=xj*xj+yj*yj+zj*zj
1885           rrmij=1.0D0/rij
1886           rij=dsqrt(rij)
1887           rmij=1.0D0/rij
1888           r3ij=rrmij*rmij
1889           r6ij=r3ij*r3ij  
1890           cosa=dx_normi*dx_normj+dy_normi*dy_normj+dz_normi*dz_normj
1891           cosb=(xj*dx_normi+yj*dy_normi+zj*dz_normi)*rmij
1892           cosg=(xj*dx_normj+yj*dy_normj+zj*dz_normj)*rmij
1893           fac=cosa-3.0D0*cosb*cosg
1894           ev1=aaa*r6ij*r6ij
1895 c 4/26/02 - AL scaling down 1,4 repulsive VDW interactions
1896           if (j.eq.i+2) ev1=scal_el*ev1
1897           ev2=bbb*r6ij
1898           fac3=ael6i*r6ij
1899           fac4=ael3i*r3ij
1900           evdwij=ev1+ev2
1901           el1=fac3*(4.0D0+fac*fac-3.0D0*(cosb*cosb+cosg*cosg))
1902           el2=fac4*fac       
1903           eesij=el1+el2
1904 c          write (iout,*) "i",i,iteli," j",j,itelj," eesij",eesij
1905 C 12/26/95 - for the evaluation of multi-body H-bonding interactions
1906           ees0ij=4.0D0+fac*fac-3.0D0*(cosb*cosb+cosg*cosg)
1907           ees=ees+eesij
1908           evdw1=evdw1+evdwij
1909 cd          write(iout,'(2(2i3,2x),7(1pd12.4)/2(3(1pd12.4),5x)/)')
1910 cd     &      iteli,i,itelj,j,aaa,bbb,ael6i,ael3i,
1911 cd     &      1.0D0/dsqrt(rrmij),evdwij,eesij,
1912 cd     &      xmedi,ymedi,zmedi,xj,yj,zj
1913 C
1914 C Calculate contributions to the Cartesian gradient.
1915 C
1916 #ifdef SPLITELE
1917           facvdw=-6*rrmij*(ev1+evdwij) 
1918           facel=-3*rrmij*(el1+eesij)
1919           fac1=fac
1920           erij(1)=xj*rmij
1921           erij(2)=yj*rmij
1922           erij(3)=zj*rmij
1923           if (calc_grad) then
1924 *
1925 * Radial derivatives. First process both termini of the fragment (i,j)
1926
1927           ggg(1)=facel*xj
1928           ggg(2)=facel*yj
1929           ggg(3)=facel*zj
1930           do k=1,3
1931             ghalf=0.5D0*ggg(k)
1932             gelc(k,i)=gelc(k,i)+ghalf
1933             gelc(k,j)=gelc(k,j)+ghalf
1934           enddo
1935 *
1936 * Loop over residues i+1 thru j-1.
1937 *
1938           do k=i+1,j-1
1939             do l=1,3
1940               gelc(l,k)=gelc(l,k)+ggg(l)
1941             enddo
1942           enddo
1943           ggg(1)=facvdw*xj
1944           ggg(2)=facvdw*yj
1945           ggg(3)=facvdw*zj
1946           do k=1,3
1947             ghalf=0.5D0*ggg(k)
1948             gvdwpp(k,i)=gvdwpp(k,i)+ghalf
1949             gvdwpp(k,j)=gvdwpp(k,j)+ghalf
1950           enddo
1951 *
1952 * Loop over residues i+1 thru j-1.
1953 *
1954           do k=i+1,j-1
1955             do l=1,3
1956               gvdwpp(l,k)=gvdwpp(l,k)+ggg(l)
1957             enddo
1958           enddo
1959 #else
1960           facvdw=ev1+evdwij 
1961           facel=el1+eesij  
1962           fac1=fac
1963           fac=-3*rrmij*(facvdw+facvdw+facel)
1964           erij(1)=xj*rmij
1965           erij(2)=yj*rmij
1966           erij(3)=zj*rmij
1967           if (calc_grad) then
1968 *
1969 * Radial derivatives. First process both termini of the fragment (i,j)
1970
1971           ggg(1)=fac*xj
1972           ggg(2)=fac*yj
1973           ggg(3)=fac*zj
1974           do k=1,3
1975             ghalf=0.5D0*ggg(k)
1976             gelc(k,i)=gelc(k,i)+ghalf
1977             gelc(k,j)=gelc(k,j)+ghalf
1978           enddo
1979 *
1980 * Loop over residues i+1 thru j-1.
1981 *
1982           do k=i+1,j-1
1983             do l=1,3
1984               gelc(l,k)=gelc(l,k)+ggg(l)
1985             enddo
1986           enddo
1987 #endif
1988 *
1989 * Angular part
1990 *          
1991           ecosa=2.0D0*fac3*fac1+fac4
1992           fac4=-3.0D0*fac4
1993           fac3=-6.0D0*fac3
1994           ecosb=(fac3*(fac1*cosg+cosb)+cosg*fac4)
1995           ecosg=(fac3*(fac1*cosb+cosg)+cosb*fac4)
1996           do k=1,3
1997             dcosb(k)=rmij*(dc_norm(k,i)-erij(k)*cosb)
1998             dcosg(k)=rmij*(dc_norm(k,j)-erij(k)*cosg)
1999           enddo
2000 cd        print '(2i3,2(3(1pd14.5),3x))',i,j,(dcosb(k),k=1,3),
2001 cd   &          (dcosg(k),k=1,3)
2002           do k=1,3
2003             ggg(k)=ecosb*dcosb(k)+ecosg*dcosg(k) 
2004           enddo
2005           do k=1,3
2006             ghalf=0.5D0*ggg(k)
2007             gelc(k,i)=gelc(k,i)+ghalf
2008      &               +(ecosa*(dc_norm(k,j)-cosa*dc_norm(k,i))
2009      &               + ecosb*(erij(k)-cosb*dc_norm(k,i)))*vbld_inv(i+1)
2010             gelc(k,j)=gelc(k,j)+ghalf
2011      &               +(ecosa*(dc_norm(k,i)-cosa*dc_norm(k,j))
2012      &               + ecosg*(erij(k)-cosg*dc_norm(k,j)))*vbld_inv(j+1)
2013           enddo
2014           do k=i+1,j-1
2015             do l=1,3
2016               gelc(l,k)=gelc(l,k)+ggg(l)
2017             enddo
2018           enddo
2019           endif
2020
2021           IF (wel_loc.gt.0.0d0 .or. wcorr4.gt.0.0d0 .or. wcorr5.gt.0.0d0
2022      &        .or. wcorr6.gt.0.0d0 .or. wturn3.gt.0.0d0 
2023      &        .or. wturn4.gt.0.0d0 .or. wturn6.gt.0.0d0) THEN
2024 C
2025 C 9/25/99 Mixed third-order local-electrostatic terms. The local-interaction 
2026 C   energy of a peptide unit is assumed in the form of a second-order 
2027 C   Fourier series in the angles lambda1 and lambda2 (see Nishikawa et al.
2028 C   Macromolecules, 1974, 7, 797-806 for definition). This correlation terms
2029 C   are computed for EVERY pair of non-contiguous peptide groups.
2030 C
2031           if (j.lt.nres-1) then
2032             j1=j+1
2033             j2=j-1
2034           else
2035             j1=j-1
2036             j2=j-2
2037           endif
2038           kkk=0
2039           do k=1,2
2040             do l=1,2
2041               kkk=kkk+1
2042               muij(kkk)=mu(k,i)*mu(l,j)
2043             enddo
2044           enddo  
2045 cd         write (iout,*) 'EELEC: i',i,' j',j
2046 cd          write (iout,*) 'j',j,' j1',j1,' j2',j2
2047 cd          write(iout,*) 'muij',muij
2048           ury=scalar(uy(1,i),erij)
2049           urz=scalar(uz(1,i),erij)
2050           vry=scalar(uy(1,j),erij)
2051           vrz=scalar(uz(1,j),erij)
2052           a22=scalar(uy(1,i),uy(1,j))-3*ury*vry
2053           a23=scalar(uy(1,i),uz(1,j))-3*ury*vrz
2054           a32=scalar(uz(1,i),uy(1,j))-3*urz*vry
2055           a33=scalar(uz(1,i),uz(1,j))-3*urz*vrz
2056 C For diagnostics only
2057 cd          a22=1.0d0
2058 cd          a23=1.0d0
2059 cd          a32=1.0d0
2060 cd          a33=1.0d0
2061           fac=dsqrt(-ael6i)*r3ij
2062 cd          write (2,*) 'fac=',fac
2063 C For diagnostics only
2064 cd          fac=1.0d0
2065           a22=a22*fac
2066           a23=a23*fac
2067           a32=a32*fac
2068           a33=a33*fac
2069 cd          write (iout,'(4i5,4f10.5)')
2070 cd     &     i,itortyp(itype(i)),j,itortyp(itype(j)),a22,a23,a32,a33
2071 cd          write (iout,'(6f10.5)') (muij(k),k=1,4),fac,eel_loc_ij
2072 cd          write (iout,'(2(3f10.5,5x)/2(3f10.5,5x))') (uy(k,i),k=1,3),
2073 cd     &      (uz(k,i),k=1,3),(uy(k,j),k=1,3),(uz(k,j),k=1,3)
2074 cd          write (iout,'(4f10.5)') 
2075 cd     &      scalar(uy(1,i),uy(1,j)),scalar(uy(1,i),uz(1,j)),
2076 cd     &      scalar(uz(1,i),uy(1,j)),scalar(uz(1,i),uz(1,j))
2077 cd          write (iout,'(4f10.5)') ury,urz,vry,vrz
2078 cd           write (iout,'(2i3,9f10.5/)') i,j,
2079 cd     &      fac22,a22,fac23,a23,fac32,a32,fac33,a33,eel_loc_ij
2080           if (calc_grad) then
2081 C Derivatives of the elements of A in virtual-bond vectors
2082           call unormderiv(erij(1),unmat(1,1),rmij,erder(1,1))
2083 cd          do k=1,3
2084 cd            do l=1,3
2085 cd              erder(k,l)=0.0d0
2086 cd            enddo
2087 cd          enddo
2088           do k=1,3
2089             uryg(k,1)=scalar(erder(1,k),uy(1,i))
2090             uryg(k,2)=scalar(uygrad(1,k,1,i),erij(1))
2091             uryg(k,3)=scalar(uygrad(1,k,2,i),erij(1))
2092             urzg(k,1)=scalar(erder(1,k),uz(1,i))
2093             urzg(k,2)=scalar(uzgrad(1,k,1,i),erij(1))
2094             urzg(k,3)=scalar(uzgrad(1,k,2,i),erij(1))
2095             vryg(k,1)=scalar(erder(1,k),uy(1,j))
2096             vryg(k,2)=scalar(uygrad(1,k,1,j),erij(1))
2097             vryg(k,3)=scalar(uygrad(1,k,2,j),erij(1))
2098             vrzg(k,1)=scalar(erder(1,k),uz(1,j))
2099             vrzg(k,2)=scalar(uzgrad(1,k,1,j),erij(1))
2100             vrzg(k,3)=scalar(uzgrad(1,k,2,j),erij(1))
2101           enddo
2102 cd          do k=1,3
2103 cd            do l=1,3
2104 cd              uryg(k,l)=0.0d0
2105 cd              urzg(k,l)=0.0d0
2106 cd              vryg(k,l)=0.0d0
2107 cd              vrzg(k,l)=0.0d0
2108 cd            enddo
2109 cd          enddo
2110 C Compute radial contributions to the gradient
2111           facr=-3.0d0*rrmij
2112           a22der=a22*facr
2113           a23der=a23*facr
2114           a32der=a32*facr
2115           a33der=a33*facr
2116 cd          a22der=0.0d0
2117 cd          a23der=0.0d0
2118 cd          a32der=0.0d0
2119 cd          a33der=0.0d0
2120           agg(1,1)=a22der*xj
2121           agg(2,1)=a22der*yj
2122           agg(3,1)=a22der*zj
2123           agg(1,2)=a23der*xj
2124           agg(2,2)=a23der*yj
2125           agg(3,2)=a23der*zj
2126           agg(1,3)=a32der*xj
2127           agg(2,3)=a32der*yj
2128           agg(3,3)=a32der*zj
2129           agg(1,4)=a33der*xj
2130           agg(2,4)=a33der*yj
2131           agg(3,4)=a33der*zj
2132 C Add the contributions coming from er
2133           fac3=-3.0d0*fac
2134           do k=1,3
2135             agg(k,1)=agg(k,1)+fac3*(uryg(k,1)*vry+vryg(k,1)*ury)
2136             agg(k,2)=agg(k,2)+fac3*(uryg(k,1)*vrz+vrzg(k,1)*ury)
2137             agg(k,3)=agg(k,3)+fac3*(urzg(k,1)*vry+vryg(k,1)*urz)
2138             agg(k,4)=agg(k,4)+fac3*(urzg(k,1)*vrz+vrzg(k,1)*urz)
2139           enddo
2140           do k=1,3
2141 C Derivatives in DC(i) 
2142             ghalf1=0.5d0*agg(k,1)
2143             ghalf2=0.5d0*agg(k,2)
2144             ghalf3=0.5d0*agg(k,3)
2145             ghalf4=0.5d0*agg(k,4)
2146             aggi(k,1)=fac*(scalar(uygrad(1,k,1,i),uy(1,j))
2147      &      -3.0d0*uryg(k,2)*vry)+ghalf1
2148             aggi(k,2)=fac*(scalar(uygrad(1,k,1,i),uz(1,j))
2149      &      -3.0d0*uryg(k,2)*vrz)+ghalf2
2150             aggi(k,3)=fac*(scalar(uzgrad(1,k,1,i),uy(1,j))
2151      &      -3.0d0*urzg(k,2)*vry)+ghalf3
2152             aggi(k,4)=fac*(scalar(uzgrad(1,k,1,i),uz(1,j))
2153      &      -3.0d0*urzg(k,2)*vrz)+ghalf4
2154 C Derivatives in DC(i+1)
2155             aggi1(k,1)=fac*(scalar(uygrad(1,k,2,i),uy(1,j))
2156      &      -3.0d0*uryg(k,3)*vry)+agg(k,1)
2157             aggi1(k,2)=fac*(scalar(uygrad(1,k,2,i),uz(1,j))
2158      &      -3.0d0*uryg(k,3)*vrz)+agg(k,2)
2159             aggi1(k,3)=fac*(scalar(uzgrad(1,k,2,i),uy(1,j))
2160      &      -3.0d0*urzg(k,3)*vry)+agg(k,3)
2161             aggi1(k,4)=fac*(scalar(uzgrad(1,k,2,i),uz(1,j))
2162      &      -3.0d0*urzg(k,3)*vrz)+agg(k,4)
2163 C Derivatives in DC(j)
2164             aggj(k,1)=fac*(scalar(uygrad(1,k,1,j),uy(1,i))
2165      &      -3.0d0*vryg(k,2)*ury)+ghalf1
2166             aggj(k,2)=fac*(scalar(uzgrad(1,k,1,j),uy(1,i))
2167      &      -3.0d0*vrzg(k,2)*ury)+ghalf2
2168             aggj(k,3)=fac*(scalar(uygrad(1,k,1,j),uz(1,i))
2169      &      -3.0d0*vryg(k,2)*urz)+ghalf3
2170             aggj(k,4)=fac*(scalar(uzgrad(1,k,1,j),uz(1,i)) 
2171      &      -3.0d0*vrzg(k,2)*urz)+ghalf4
2172 C Derivatives in DC(j+1) or DC(nres-1)
2173             aggj1(k,1)=fac*(scalar(uygrad(1,k,2,j),uy(1,i))
2174      &      -3.0d0*vryg(k,3)*ury)
2175             aggj1(k,2)=fac*(scalar(uzgrad(1,k,2,j),uy(1,i))
2176      &      -3.0d0*vrzg(k,3)*ury)
2177             aggj1(k,3)=fac*(scalar(uygrad(1,k,2,j),uz(1,i))
2178      &      -3.0d0*vryg(k,3)*urz)
2179             aggj1(k,4)=fac*(scalar(uzgrad(1,k,2,j),uz(1,i)) 
2180      &      -3.0d0*vrzg(k,3)*urz)
2181 cd            aggi(k,1)=ghalf1
2182 cd            aggi(k,2)=ghalf2
2183 cd            aggi(k,3)=ghalf3
2184 cd            aggi(k,4)=ghalf4
2185 C Derivatives in DC(i+1)
2186 cd            aggi1(k,1)=agg(k,1)
2187 cd            aggi1(k,2)=agg(k,2)
2188 cd            aggi1(k,3)=agg(k,3)
2189 cd            aggi1(k,4)=agg(k,4)
2190 C Derivatives in DC(j)
2191 cd            aggj(k,1)=ghalf1
2192 cd            aggj(k,2)=ghalf2
2193 cd            aggj(k,3)=ghalf3
2194 cd            aggj(k,4)=ghalf4
2195 C Derivatives in DC(j+1)
2196 cd            aggj1(k,1)=0.0d0
2197 cd            aggj1(k,2)=0.0d0
2198 cd            aggj1(k,3)=0.0d0
2199 cd            aggj1(k,4)=0.0d0
2200             if (j.eq.nres-1 .and. i.lt.j-2) then
2201               do l=1,4
2202                 aggj1(k,l)=aggj1(k,l)+agg(k,l)
2203 cd                aggj1(k,l)=agg(k,l)
2204               enddo
2205             endif
2206           enddo
2207           endif
2208 c          goto 11111
2209 C Check the loc-el terms by numerical integration
2210           acipa(1,1)=a22
2211           acipa(1,2)=a23
2212           acipa(2,1)=a32
2213           acipa(2,2)=a33
2214           a22=-a22
2215           a23=-a23
2216           do l=1,2
2217             do k=1,3
2218               agg(k,l)=-agg(k,l)
2219               aggi(k,l)=-aggi(k,l)
2220               aggi1(k,l)=-aggi1(k,l)
2221               aggj(k,l)=-aggj(k,l)
2222               aggj1(k,l)=-aggj1(k,l)
2223             enddo
2224           enddo
2225           if (j.lt.nres-1) then
2226             a22=-a22
2227             a32=-a32
2228             do l=1,3,2
2229               do k=1,3
2230                 agg(k,l)=-agg(k,l)
2231                 aggi(k,l)=-aggi(k,l)
2232                 aggi1(k,l)=-aggi1(k,l)
2233                 aggj(k,l)=-aggj(k,l)
2234                 aggj1(k,l)=-aggj1(k,l)
2235               enddo
2236             enddo
2237           else
2238             a22=-a22
2239             a23=-a23
2240             a32=-a32
2241             a33=-a33
2242             do l=1,4
2243               do k=1,3
2244                 agg(k,l)=-agg(k,l)
2245                 aggi(k,l)=-aggi(k,l)
2246                 aggi1(k,l)=-aggi1(k,l)
2247                 aggj(k,l)=-aggj(k,l)
2248                 aggj1(k,l)=-aggj1(k,l)
2249               enddo
2250             enddo 
2251           endif    
2252           ENDIF ! WCORR
2253 11111     continue
2254           IF (wel_loc.gt.0.0d0) THEN
2255 C Contribution to the local-electrostatic energy coming from the i-j pair
2256           eel_loc_ij=a22*muij(1)+a23*muij(2)+a32*muij(3)
2257      &     +a33*muij(4)
2258 cd          write (iout,*) 'i',i,' j',j,' eel_loc_ij',eel_loc_ij
2259 cd          write (iout,*) a22,muij(1),a23,muij(2),a32,muij(3)
2260           eel_loc=eel_loc+eel_loc_ij
2261 C Partial derivatives in virtual-bond dihedral angles gamma
2262           if (calc_grad) then
2263           if (i.gt.1)
2264      &    gel_loc_loc(i-1)=gel_loc_loc(i-1)+ 
2265      &            a22*muder(1,i)*mu(1,j)+a23*muder(1,i)*mu(2,j)
2266      &           +a32*muder(2,i)*mu(1,j)+a33*muder(2,i)*mu(2,j)
2267           gel_loc_loc(j-1)=gel_loc_loc(j-1)+ 
2268      &            a22*mu(1,i)*muder(1,j)+a23*mu(1,i)*muder(2,j)
2269      &           +a32*mu(2,i)*muder(1,j)+a33*mu(2,i)*muder(2,j)
2270 cd          call checkint3(i,j,mu1,mu2,a22,a23,a32,a33,acipa,eel_loc_ij)
2271 cd          write(iout,*) 'agg  ',agg
2272 cd          write(iout,*) 'aggi ',aggi
2273 cd          write(iout,*) 'aggi1',aggi1
2274 cd          write(iout,*) 'aggj ',aggj
2275 cd          write(iout,*) 'aggj1',aggj1
2276
2277 C Derivatives of eello in DC(i+1) thru DC(j-1) or DC(nres-2)
2278           do l=1,3
2279             ggg(l)=agg(l,1)*muij(1)+
2280      &          agg(l,2)*muij(2)+agg(l,3)*muij(3)+agg(l,4)*muij(4)
2281           enddo
2282           do k=i+2,j2
2283             do l=1,3
2284               gel_loc(l,k)=gel_loc(l,k)+ggg(l)
2285             enddo
2286           enddo
2287 C Remaining derivatives of eello
2288           do l=1,3
2289             gel_loc(l,i)=gel_loc(l,i)+aggi(l,1)*muij(1)+
2290      &          aggi(l,2)*muij(2)+aggi(l,3)*muij(3)+aggi(l,4)*muij(4)
2291             gel_loc(l,i+1)=gel_loc(l,i+1)+aggi1(l,1)*muij(1)+
2292      &          aggi1(l,2)*muij(2)+aggi1(l,3)*muij(3)+aggi1(l,4)*muij(4)
2293             gel_loc(l,j)=gel_loc(l,j)+aggj(l,1)*muij(1)+
2294      &          aggj(l,2)*muij(2)+aggj(l,3)*muij(3)+aggj(l,4)*muij(4)
2295             gel_loc(l,j1)=gel_loc(l,j1)+aggj1(l,1)*muij(1)+
2296      &          aggj1(l,2)*muij(2)+aggj1(l,3)*muij(3)+aggj1(l,4)*muij(4)
2297           enddo
2298           endif
2299           ENDIF
2300           if (wturn3.gt.0.0d0 .or. wturn4.gt.0.0d0) then
2301 C Contributions from turns
2302             a_temp(1,1)=a22
2303             a_temp(1,2)=a23
2304             a_temp(2,1)=a32
2305             a_temp(2,2)=a33
2306             call eturn34(i,j,eello_turn3,eello_turn4)
2307           endif
2308 C Change 12/26/95 to calculate four-body contributions to H-bonding energy
2309           if (j.gt.i+1 .and. num_conti.le.maxconts) then
2310 C
2311 C Calculate the contact function. The ith column of the array JCONT will 
2312 C contain the numbers of atoms that make contacts with the atom I (of numbers
2313 C greater than I). The arrays FACONT and GACONT will contain the values of
2314 C the contact function and its derivative.
2315 c           r0ij=1.02D0*rpp(iteli,itelj)
2316 c           r0ij=1.11D0*rpp(iteli,itelj)
2317             r0ij=2.20D0*rpp(iteli,itelj)
2318 c           r0ij=1.55D0*rpp(iteli,itelj)
2319             call gcont(rij,r0ij,1.0D0,0.2d0*r0ij,fcont,fprimcont)
2320             if (fcont.gt.0.0D0) then
2321               num_conti=num_conti+1
2322               if (num_conti.gt.maxconts) then
2323                 write (iout,*) 'WARNING - max. # of contacts exceeded;',
2324      &                         ' will skip next contacts for this conf.'
2325               else
2326                 jcont_hb(num_conti,i)=j
2327                 IF (wcorr4.gt.0.0d0 .or. wcorr5.gt.0.0d0 .or. 
2328      &          wcorr6.gt.0.0d0 .or. wturn6.gt.0.0d0) THEN
2329 C 9/30/99 (AL) - store components necessary to evaluate higher-order loc-el
2330 C  terms.
2331                 d_cont(num_conti,i)=rij
2332 cd                write (2,'(3e15.5)') rij,r0ij+0.2d0*r0ij,rij
2333 C     --- Electrostatic-interaction matrix --- 
2334                 a_chuj(1,1,num_conti,i)=a22
2335                 a_chuj(1,2,num_conti,i)=a23
2336                 a_chuj(2,1,num_conti,i)=a32
2337                 a_chuj(2,2,num_conti,i)=a33
2338 C     --- Gradient of rij
2339                 do kkk=1,3
2340                   grij_hb_cont(kkk,num_conti,i)=erij(kkk)
2341                 enddo
2342 c             if (i.eq.1) then
2343 c                a_chuj(1,1,num_conti,i)=-0.61d0
2344 c                a_chuj(1,2,num_conti,i)= 0.4d0
2345 c                a_chuj(2,1,num_conti,i)= 0.65d0
2346 c                a_chuj(2,2,num_conti,i)= 0.50d0
2347 c             else if (i.eq.2) then
2348 c                a_chuj(1,1,num_conti,i)= 0.0d0
2349 c                a_chuj(1,2,num_conti,i)= 0.0d0
2350 c                a_chuj(2,1,num_conti,i)= 0.0d0
2351 c                a_chuj(2,2,num_conti,i)= 0.0d0
2352 c             endif
2353 C     --- and its gradients
2354 cd                write (iout,*) 'i',i,' j',j
2355 cd                do kkk=1,3
2356 cd                write (iout,*) 'iii 1 kkk',kkk
2357 cd                write (iout,*) agg(kkk,:)
2358 cd                enddo
2359 cd                do kkk=1,3
2360 cd                write (iout,*) 'iii 2 kkk',kkk
2361 cd                write (iout,*) aggi(kkk,:)
2362 cd                enddo
2363 cd                do kkk=1,3
2364 cd                write (iout,*) 'iii 3 kkk',kkk
2365 cd                write (iout,*) aggi1(kkk,:)
2366 cd                enddo
2367 cd                do kkk=1,3
2368 cd                write (iout,*) 'iii 4 kkk',kkk
2369 cd                write (iout,*) aggj(kkk,:)
2370 cd                enddo
2371 cd                do kkk=1,3
2372 cd                write (iout,*) 'iii 5 kkk',kkk
2373 cd                write (iout,*) aggj1(kkk,:)
2374 cd                enddo
2375                 kkll=0
2376                 do k=1,2
2377                   do l=1,2
2378                     kkll=kkll+1
2379                     do m=1,3
2380                       a_chuj_der(k,l,m,1,num_conti,i)=agg(m,kkll)
2381                       a_chuj_der(k,l,m,2,num_conti,i)=aggi(m,kkll)
2382                       a_chuj_der(k,l,m,3,num_conti,i)=aggi1(m,kkll)
2383                       a_chuj_der(k,l,m,4,num_conti,i)=aggj(m,kkll)
2384                       a_chuj_der(k,l,m,5,num_conti,i)=aggj1(m,kkll)
2385 c                      do mm=1,5
2386 c                      a_chuj_der(k,l,m,mm,num_conti,i)=0.0d0
2387 c                      enddo
2388                     enddo
2389                   enddo
2390                 enddo
2391                 ENDIF
2392                 IF (wcorr4.eq.0.0d0 .and. wcorr.gt.0.0d0) THEN
2393 C Calculate contact energies
2394                 cosa4=4.0D0*cosa
2395                 wij=cosa-3.0D0*cosb*cosg
2396                 cosbg1=cosb+cosg
2397                 cosbg2=cosb-cosg
2398 c               fac3=dsqrt(-ael6i)/r0ij**3     
2399                 fac3=dsqrt(-ael6i)*r3ij
2400                 ees0pij=dsqrt(4.0D0+cosa4+wij*wij-3.0D0*cosbg1*cosbg1)
2401                 ees0mij=dsqrt(4.0D0-cosa4+wij*wij-3.0D0*cosbg2*cosbg2)
2402 c               ees0mij=0.0D0
2403                 ees0p(num_conti,i)=0.5D0*fac3*(ees0pij+ees0mij)
2404                 ees0m(num_conti,i)=0.5D0*fac3*(ees0pij-ees0mij)
2405 C Diagnostics. Comment out or remove after debugging!
2406 c               ees0p(num_conti,i)=0.5D0*fac3*ees0pij
2407 c               ees0m(num_conti,i)=0.5D0*fac3*ees0mij
2408 c               ees0m(num_conti,i)=0.0D0
2409 C End diagnostics.
2410 c                write (iout,*) 'i=',i,' j=',j,' rij=',rij,' r0ij=',r0ij,
2411 c     & ' ees0ij=',ees0p(num_conti,i),ees0m(num_conti,i),' fcont=',fcont
2412                 facont_hb(num_conti,i)=fcont
2413                 if (calc_grad) then
2414 C Angular derivatives of the contact function
2415                 ees0pij1=fac3/ees0pij 
2416                 ees0mij1=fac3/ees0mij
2417                 fac3p=-3.0D0*fac3*rrmij
2418                 ees0pijp=0.5D0*fac3p*(ees0pij+ees0mij)
2419                 ees0mijp=0.5D0*fac3p*(ees0pij-ees0mij)
2420 c               ees0mij1=0.0D0
2421                 ecosa1=       ees0pij1*( 1.0D0+0.5D0*wij)
2422                 ecosb1=-1.5D0*ees0pij1*(wij*cosg+cosbg1)
2423                 ecosg1=-1.5D0*ees0pij1*(wij*cosb+cosbg1)
2424                 ecosa2=       ees0mij1*(-1.0D0+0.5D0*wij)
2425                 ecosb2=-1.5D0*ees0mij1*(wij*cosg+cosbg2) 
2426                 ecosg2=-1.5D0*ees0mij1*(wij*cosb-cosbg2)
2427                 ecosap=ecosa1+ecosa2
2428                 ecosbp=ecosb1+ecosb2
2429                 ecosgp=ecosg1+ecosg2
2430                 ecosam=ecosa1-ecosa2
2431                 ecosbm=ecosb1-ecosb2
2432                 ecosgm=ecosg1-ecosg2
2433 C Diagnostics
2434 c               ecosap=ecosa1
2435 c               ecosbp=ecosb1
2436 c               ecosgp=ecosg1
2437 c               ecosam=0.0D0
2438 c               ecosbm=0.0D0
2439 c               ecosgm=0.0D0
2440 C End diagnostics
2441                 fprimcont=fprimcont/rij
2442 cd              facont_hb(num_conti,i)=1.0D0
2443 C Following line is for diagnostics.
2444 cd              fprimcont=0.0D0
2445                 do k=1,3
2446                   dcosb(k)=rmij*(dc_norm(k,i)-erij(k)*cosb)
2447                   dcosg(k)=rmij*(dc_norm(k,j)-erij(k)*cosg)
2448                 enddo
2449                 do k=1,3
2450                   gggp(k)=ecosbp*dcosb(k)+ecosgp*dcosg(k)
2451                   gggm(k)=ecosbm*dcosb(k)+ecosgm*dcosg(k)
2452                 enddo
2453                 gggp(1)=gggp(1)+ees0pijp*xj
2454                 gggp(2)=gggp(2)+ees0pijp*yj
2455                 gggp(3)=gggp(3)+ees0pijp*zj
2456                 gggm(1)=gggm(1)+ees0mijp*xj
2457                 gggm(2)=gggm(2)+ees0mijp*yj
2458                 gggm(3)=gggm(3)+ees0mijp*zj
2459 C Derivatives due to the contact function
2460                 gacont_hbr(1,num_conti,i)=fprimcont*xj
2461                 gacont_hbr(2,num_conti,i)=fprimcont*yj
2462                 gacont_hbr(3,num_conti,i)=fprimcont*zj
2463                 do k=1,3
2464                   ghalfp=0.5D0*gggp(k)
2465                   ghalfm=0.5D0*gggm(k)
2466                   gacontp_hb1(k,num_conti,i)=ghalfp
2467      &              +(ecosap*(dc_norm(k,j)-cosa*dc_norm(k,i))
2468      &              + ecosbp*(erij(k)-cosb*dc_norm(k,i)))*vbld_inv(i+1)
2469                   gacontp_hb2(k,num_conti,i)=ghalfp
2470      &              +(ecosap*(dc_norm(k,i)-cosa*dc_norm(k,j))
2471      &              + ecosgp*(erij(k)-cosg*dc_norm(k,j)))*vbld_inv(j+1)
2472                   gacontp_hb3(k,num_conti,i)=gggp(k)
2473                   gacontm_hb1(k,num_conti,i)=ghalfm
2474      &              +(ecosam*(dc_norm(k,j)-cosa*dc_norm(k,i))
2475      &              + ecosbm*(erij(k)-cosb*dc_norm(k,i)))*vbld_inv(i+1)
2476                   gacontm_hb2(k,num_conti,i)=ghalfm
2477      &              +(ecosam*(dc_norm(k,i)-cosa*dc_norm(k,j))
2478      &              + ecosgm*(erij(k)-cosg*dc_norm(k,j)))*vbld_inv(j+1)
2479                   gacontm_hb3(k,num_conti,i)=gggm(k)
2480                 enddo
2481                 endif
2482 C Diagnostics. Comment out or remove after debugging!
2483 cdiag           do k=1,3
2484 cdiag             gacontp_hb1(k,num_conti,i)=0.0D0
2485 cdiag             gacontp_hb2(k,num_conti,i)=0.0D0
2486 cdiag             gacontp_hb3(k,num_conti,i)=0.0D0
2487 cdiag             gacontm_hb1(k,num_conti,i)=0.0D0
2488 cdiag             gacontm_hb2(k,num_conti,i)=0.0D0
2489 cdiag             gacontm_hb3(k,num_conti,i)=0.0D0
2490 cdiag           enddo
2491               ENDIF ! wcorr
2492               endif  ! num_conti.le.maxconts
2493             endif  ! fcont.gt.0
2494           endif    ! j.gt.i+1
2495  1216     continue
2496         enddo ! j
2497         num_cont_hb(i)=num_conti
2498  1215   continue
2499       enddo   ! i
2500 cd      do i=1,nres
2501 cd        write (iout,'(i3,3f10.5,5x,3f10.5)') 
2502 cd     &     i,(gel_loc(k,i),k=1,3),gel_loc_loc(i)
2503 cd      enddo
2504 c 12/7/99 Adam eello_turn3 will be considered as a separate energy term
2505 ccc      eel_loc=eel_loc+eello_turn3
2506       return
2507       end
2508 C-----------------------------------------------------------------------------
2509       subroutine eturn34(i,j,eello_turn3,eello_turn4)
2510 C Third- and fourth-order contributions from turns
2511       implicit real*8 (a-h,o-z)
2512       include 'DIMENSIONS'
2513       include 'DIMENSIONS.ZSCOPT'
2514       include 'COMMON.IOUNITS'
2515       include 'COMMON.GEO'
2516       include 'COMMON.VAR'
2517       include 'COMMON.LOCAL'
2518       include 'COMMON.CHAIN'
2519       include 'COMMON.DERIV'
2520       include 'COMMON.INTERACT'
2521       include 'COMMON.CONTACTS'
2522       include 'COMMON.TORSION'
2523       include 'COMMON.VECTORS'
2524       include 'COMMON.FFIELD'
2525       dimension ggg(3)
2526       double precision auxmat(2,2),auxmat1(2,2),auxmat2(2,2),pizda(2,2),
2527      &  e1t(2,2),e2t(2,2),e3t(2,2),e1tder(2,2),e2tder(2,2),e3tder(2,2),
2528      &  e1a(2,2),ae3(2,2),ae3e2(2,2),auxvec(2),auxvec1(2)
2529       double precision agg(3,4),aggi(3,4),aggi1(3,4),
2530      &    aggj(3,4),aggj1(3,4),a_temp(2,2)
2531       common /locel/ a_temp,agg,aggi,aggi1,aggj,aggj1,j1,j2
2532       if (j.eq.i+2) then
2533 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
2534 C
2535 C               Third-order contributions
2536 C        
2537 C                 (i+2)o----(i+3)
2538 C                      | |
2539 C                      | |
2540 C                 (i+1)o----i
2541 C
2542 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC   
2543 cd        call checkint_turn3(i,a_temp,eello_turn3_num)
2544         call matmat2(EUg(1,1,i+1),EUg(1,1,i+2),auxmat(1,1))
2545         call transpose2(auxmat(1,1),auxmat1(1,1))
2546         call matmat2(a_temp(1,1),auxmat1(1,1),pizda(1,1))
2547         eello_turn3=eello_turn3+0.5d0*(pizda(1,1)+pizda(2,2))
2548 cd        write (2,*) 'i,',i,' j',j,'eello_turn3',
2549 cd     &    0.5d0*(pizda(1,1)+pizda(2,2)),
2550 cd     &    ' eello_turn3_num',4*eello_turn3_num
2551         if (calc_grad) then
2552 C Derivatives in gamma(i)
2553         call matmat2(EUgder(1,1,i+1),EUg(1,1,i+2),auxmat2(1,1))
2554         call transpose2(auxmat2(1,1),pizda(1,1))
2555         call matmat2(a_temp(1,1),pizda(1,1),pizda(1,1))
2556         gel_loc_turn3(i)=gel_loc_turn3(i)+0.5d0*(pizda(1,1)+pizda(2,2))
2557 C Derivatives in gamma(i+1)
2558         call matmat2(EUg(1,1,i+1),EUgder(1,1,i+2),auxmat2(1,1))
2559         call transpose2(auxmat2(1,1),pizda(1,1))
2560         call matmat2(a_temp(1,1),pizda(1,1),pizda(1,1))
2561         gel_loc_turn3(i+1)=gel_loc_turn3(i+1)
2562      &    +0.5d0*(pizda(1,1)+pizda(2,2))
2563 C Cartesian derivatives
2564         do l=1,3
2565           a_temp(1,1)=aggi(l,1)
2566           a_temp(1,2)=aggi(l,2)
2567           a_temp(2,1)=aggi(l,3)
2568           a_temp(2,2)=aggi(l,4)
2569           call matmat2(a_temp(1,1),auxmat1(1,1),pizda(1,1))
2570           gcorr3_turn(l,i)=gcorr3_turn(l,i)
2571      &      +0.5d0*(pizda(1,1)+pizda(2,2))
2572           a_temp(1,1)=aggi1(l,1)
2573           a_temp(1,2)=aggi1(l,2)
2574           a_temp(2,1)=aggi1(l,3)
2575           a_temp(2,2)=aggi1(l,4)
2576           call matmat2(a_temp(1,1),auxmat1(1,1),pizda(1,1))
2577           gcorr3_turn(l,i+1)=gcorr3_turn(l,i+1)
2578      &      +0.5d0*(pizda(1,1)+pizda(2,2))
2579           a_temp(1,1)=aggj(l,1)
2580           a_temp(1,2)=aggj(l,2)
2581           a_temp(2,1)=aggj(l,3)
2582           a_temp(2,2)=aggj(l,4)
2583           call matmat2(a_temp(1,1),auxmat1(1,1),pizda(1,1))
2584           gcorr3_turn(l,j)=gcorr3_turn(l,j)
2585      &      +0.5d0*(pizda(1,1)+pizda(2,2))
2586           a_temp(1,1)=aggj1(l,1)
2587           a_temp(1,2)=aggj1(l,2)
2588           a_temp(2,1)=aggj1(l,3)
2589           a_temp(2,2)=aggj1(l,4)
2590           call matmat2(a_temp(1,1),auxmat1(1,1),pizda(1,1))
2591           gcorr3_turn(l,j1)=gcorr3_turn(l,j1)
2592      &      +0.5d0*(pizda(1,1)+pizda(2,2))
2593         enddo
2594         endif
2595       else if (j.eq.i+3) then
2596 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
2597 C
2598 C               Fourth-order contributions
2599 C        
2600 C                 (i+3)o----(i+4)
2601 C                     /  |
2602 C               (i+2)o   |
2603 C                     \  |
2604 C                 (i+1)o----i
2605 C
2606 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC   
2607 cd        call checkint_turn4(i,a_temp,eello_turn4_num)
2608         iti1=itortyp(itype(i+1))
2609         iti2=itortyp(itype(i+2))
2610         iti3=itortyp(itype(i+3))
2611         call transpose2(EUg(1,1,i+1),e1t(1,1))
2612         call transpose2(Eug(1,1,i+2),e2t(1,1))
2613         call transpose2(Eug(1,1,i+3),e3t(1,1))
2614         call matmat2(e1t(1,1),a_temp(1,1),e1a(1,1))
2615         call matvec2(e1a(1,1),Ub2(1,i+3),auxvec(1))
2616         s1=scalar2(b1(1,iti2),auxvec(1))
2617         call matmat2(a_temp(1,1),e3t(1,1),ae3(1,1))
2618         call matvec2(ae3(1,1),Ub2(1,i+2),auxvec(1)) 
2619         s2=scalar2(b1(1,iti1),auxvec(1))
2620         call matmat2(ae3(1,1),e2t(1,1),ae3e2(1,1))
2621         call matmat2(ae3e2(1,1),e1t(1,1),pizda(1,1))
2622         s3=0.5d0*(pizda(1,1)+pizda(2,2))
2623         eello_turn4=eello_turn4-(s1+s2+s3)
2624 cd        write (2,*) 'i,',i,' j',j,'eello_turn4',-(s1+s2+s3),
2625 cd     &    ' eello_turn4_num',8*eello_turn4_num
2626 C Derivatives in gamma(i)
2627         if (calc_grad) then
2628         call transpose2(EUgder(1,1,i+1),e1tder(1,1))
2629         call matmat2(e1tder(1,1),a_temp(1,1),auxmat(1,1))
2630         call matvec2(auxmat(1,1),Ub2(1,i+3),auxvec(1))
2631         s1=scalar2(b1(1,iti2),auxvec(1))
2632         call matmat2(ae3e2(1,1),e1tder(1,1),pizda(1,1))
2633         s3=0.5d0*(pizda(1,1)+pizda(2,2))
2634         gel_loc_turn4(i)=gel_loc_turn4(i)-(s1+s3)
2635 C Derivatives in gamma(i+1)
2636         call transpose2(EUgder(1,1,i+2),e2tder(1,1))
2637         call matvec2(ae3(1,1),Ub2der(1,i+2),auxvec(1)) 
2638         s2=scalar2(b1(1,iti1),auxvec(1))
2639         call matmat2(ae3(1,1),e2tder(1,1),auxmat(1,1))
2640         call matmat2(auxmat(1,1),e1t(1,1),pizda(1,1))
2641         s3=0.5d0*(pizda(1,1)+pizda(2,2))
2642         gel_loc_turn4(i+1)=gel_loc_turn4(i+1)-(s2+s3)
2643 C Derivatives in gamma(i+2)
2644         call transpose2(EUgder(1,1,i+3),e3tder(1,1))
2645         call matvec2(e1a(1,1),Ub2der(1,i+3),auxvec(1))
2646         s1=scalar2(b1(1,iti2),auxvec(1))
2647         call matmat2(a_temp(1,1),e3tder(1,1),auxmat(1,1))
2648         call matvec2(auxmat(1,1),Ub2(1,i+2),auxvec(1)) 
2649         s2=scalar2(b1(1,iti1),auxvec(1))
2650         call matmat2(auxmat(1,1),e2t(1,1),auxmat(1,1))
2651         call matmat2(auxmat(1,1),e1t(1,1),pizda(1,1))
2652         s3=0.5d0*(pizda(1,1)+pizda(2,2))
2653         gel_loc_turn4(i+2)=gel_loc_turn4(i+2)-(s1+s2+s3)
2654 C Cartesian derivatives
2655 C Derivatives of this turn contributions in DC(i+2)
2656         if (j.lt.nres-1) then
2657           do l=1,3
2658             a_temp(1,1)=agg(l,1)
2659             a_temp(1,2)=agg(l,2)
2660             a_temp(2,1)=agg(l,3)
2661             a_temp(2,2)=agg(l,4)
2662             call matmat2(e1t(1,1),a_temp(1,1),e1a(1,1))
2663             call matvec2(e1a(1,1),Ub2(1,i+3),auxvec(1))
2664             s1=scalar2(b1(1,iti2),auxvec(1))
2665             call matmat2(a_temp(1,1),e3t(1,1),ae3(1,1))
2666             call matvec2(ae3(1,1),Ub2(1,i+2),auxvec(1)) 
2667             s2=scalar2(b1(1,iti1),auxvec(1))
2668             call matmat2(ae3(1,1),e2t(1,1),ae3e2(1,1))
2669             call matmat2(ae3e2(1,1),e1t(1,1),pizda(1,1))
2670             s3=0.5d0*(pizda(1,1)+pizda(2,2))
2671             ggg(l)=-(s1+s2+s3)
2672             gcorr4_turn(l,i+2)=gcorr4_turn(l,i+2)-(s1+s2+s3)
2673           enddo
2674         endif
2675 C Remaining derivatives of this turn contribution
2676         do l=1,3
2677           a_temp(1,1)=aggi(l,1)
2678           a_temp(1,2)=aggi(l,2)
2679           a_temp(2,1)=aggi(l,3)
2680           a_temp(2,2)=aggi(l,4)
2681           call matmat2(e1t(1,1),a_temp(1,1),e1a(1,1))
2682           call matvec2(e1a(1,1),Ub2(1,i+3),auxvec(1))
2683           s1=scalar2(b1(1,iti2),auxvec(1))
2684           call matmat2(a_temp(1,1),e3t(1,1),ae3(1,1))
2685           call matvec2(ae3(1,1),Ub2(1,i+2),auxvec(1)) 
2686           s2=scalar2(b1(1,iti1),auxvec(1))
2687           call matmat2(ae3(1,1),e2t(1,1),ae3e2(1,1))
2688           call matmat2(ae3e2(1,1),e1t(1,1),pizda(1,1))
2689           s3=0.5d0*(pizda(1,1)+pizda(2,2))
2690           gcorr4_turn(l,i)=gcorr4_turn(l,i)-(s1+s2+s3)
2691           a_temp(1,1)=aggi1(l,1)
2692           a_temp(1,2)=aggi1(l,2)
2693           a_temp(2,1)=aggi1(l,3)
2694           a_temp(2,2)=aggi1(l,4)
2695           call matmat2(e1t(1,1),a_temp(1,1),e1a(1,1))
2696           call matvec2(e1a(1,1),Ub2(1,i+3),auxvec(1))
2697           s1=scalar2(b1(1,iti2),auxvec(1))
2698           call matmat2(a_temp(1,1),e3t(1,1),ae3(1,1))
2699           call matvec2(ae3(1,1),Ub2(1,i+2),auxvec(1)) 
2700           s2=scalar2(b1(1,iti1),auxvec(1))
2701           call matmat2(ae3(1,1),e2t(1,1),ae3e2(1,1))
2702           call matmat2(ae3e2(1,1),e1t(1,1),pizda(1,1))
2703           s3=0.5d0*(pizda(1,1)+pizda(2,2))
2704           gcorr4_turn(l,i+1)=gcorr4_turn(l,i+1)-(s1+s2+s3)
2705           a_temp(1,1)=aggj(l,1)
2706           a_temp(1,2)=aggj(l,2)
2707           a_temp(2,1)=aggj(l,3)
2708           a_temp(2,2)=aggj(l,4)
2709           call matmat2(e1t(1,1),a_temp(1,1),e1a(1,1))
2710           call matvec2(e1a(1,1),Ub2(1,i+3),auxvec(1))
2711           s1=scalar2(b1(1,iti2),auxvec(1))
2712           call matmat2(a_temp(1,1),e3t(1,1),ae3(1,1))
2713           call matvec2(ae3(1,1),Ub2(1,i+2),auxvec(1)) 
2714           s2=scalar2(b1(1,iti1),auxvec(1))
2715           call matmat2(ae3(1,1),e2t(1,1),ae3e2(1,1))
2716           call matmat2(ae3e2(1,1),e1t(1,1),pizda(1,1))
2717           s3=0.5d0*(pizda(1,1)+pizda(2,2))
2718           gcorr4_turn(l,j)=gcorr4_turn(l,j)-(s1+s2+s3)
2719           a_temp(1,1)=aggj1(l,1)
2720           a_temp(1,2)=aggj1(l,2)
2721           a_temp(2,1)=aggj1(l,3)
2722           a_temp(2,2)=aggj1(l,4)
2723           call matmat2(e1t(1,1),a_temp(1,1),e1a(1,1))
2724           call matvec2(e1a(1,1),Ub2(1,i+3),auxvec(1))
2725           s1=scalar2(b1(1,iti2),auxvec(1))
2726           call matmat2(a_temp(1,1),e3t(1,1),ae3(1,1))
2727           call matvec2(ae3(1,1),Ub2(1,i+2),auxvec(1)) 
2728           s2=scalar2(b1(1,iti1),auxvec(1))
2729           call matmat2(ae3(1,1),e2t(1,1),ae3e2(1,1))
2730           call matmat2(ae3e2(1,1),e1t(1,1),pizda(1,1))
2731           s3=0.5d0*(pizda(1,1)+pizda(2,2))
2732           gcorr4_turn(l,j1)=gcorr4_turn(l,j1)-(s1+s2+s3)
2733         enddo
2734         endif
2735       endif          
2736       return
2737       end
2738 C-----------------------------------------------------------------------------
2739       subroutine vecpr(u,v,w)
2740       implicit real*8(a-h,o-z)
2741       dimension u(3),v(3),w(3)
2742       w(1)=u(2)*v(3)-u(3)*v(2)
2743       w(2)=-u(1)*v(3)+u(3)*v(1)
2744       w(3)=u(1)*v(2)-u(2)*v(1)
2745       return
2746       end
2747 C-----------------------------------------------------------------------------
2748       subroutine unormderiv(u,ugrad,unorm,ungrad)
2749 C This subroutine computes the derivatives of a normalized vector u, given
2750 C the derivatives computed without normalization conditions, ugrad. Returns
2751 C ungrad.
2752       implicit none
2753       double precision u(3),ugrad(3,3),unorm,ungrad(3,3)
2754       double precision vec(3)
2755       double precision scalar
2756       integer i,j
2757 c      write (2,*) 'ugrad',ugrad
2758 c      write (2,*) 'u',u
2759       do i=1,3
2760         vec(i)=scalar(ugrad(1,i),u(1))
2761       enddo
2762 c      write (2,*) 'vec',vec
2763       do i=1,3
2764         do j=1,3
2765           ungrad(j,i)=(ugrad(j,i)-u(j)*vec(i))*unorm
2766         enddo
2767       enddo
2768 c      write (2,*) 'ungrad',ungrad
2769       return
2770       end
2771 C-----------------------------------------------------------------------------
2772       subroutine escp(evdw2,evdw2_14)
2773 C
2774 C This subroutine calculates the excluded-volume interaction energy between
2775 C peptide-group centers and side chains and its gradient in virtual-bond and
2776 C side-chain vectors.
2777 C
2778       implicit real*8 (a-h,o-z)
2779       include 'DIMENSIONS'
2780       include 'DIMENSIONS.ZSCOPT'
2781       include 'COMMON.GEO'
2782       include 'COMMON.VAR'
2783       include 'COMMON.LOCAL'
2784       include 'COMMON.CHAIN'
2785       include 'COMMON.DERIV'
2786       include 'COMMON.INTERACT'
2787       include 'COMMON.FFIELD'
2788       include 'COMMON.IOUNITS'
2789       dimension ggg(3)
2790       evdw2=0.0D0
2791       evdw2_14=0.0d0
2792 cd    print '(a)','Enter ESCP'
2793 c      write (iout,*) 'iatscp_s=',iatscp_s,' iatscp_e=',iatscp_e,
2794 c     &  ' scal14',scal14
2795       do i=iatscp_s,iatscp_e
2796         iteli=itel(i)
2797 c        write (iout,*) "i",i," iteli",iteli," nscp_gr",nscp_gr(i),
2798 c     &   " iscp",(iscpstart(i,j),iscpend(i,j),j=1,nscp_gr(i))
2799         if (iteli.eq.0) goto 1225
2800         xi=0.5D0*(c(1,i)+c(1,i+1))
2801         yi=0.5D0*(c(2,i)+c(2,i+1))
2802         zi=0.5D0*(c(3,i)+c(3,i+1))
2803
2804         do iint=1,nscp_gr(i)
2805
2806         do j=iscpstart(i,iint),iscpend(i,iint)
2807           itypj=itype(j)
2808 C Uncomment following three lines for SC-p interactions
2809 c         xj=c(1,nres+j)-xi
2810 c         yj=c(2,nres+j)-yi
2811 c         zj=c(3,nres+j)-zi
2812 C Uncomment following three lines for Ca-p interactions
2813           xj=c(1,j)-xi
2814           yj=c(2,j)-yi
2815           zj=c(3,j)-zi
2816           rrij=1.0D0/(xj*xj+yj*yj+zj*zj)
2817           fac=rrij**expon2
2818           e1=fac*fac*aad(itypj,iteli)
2819           e2=fac*bad(itypj,iteli)
2820           if (iabs(j-i) .le. 2) then
2821             e1=scal14*e1
2822             e2=scal14*e2
2823             evdw2_14=evdw2_14+e1+e2
2824           endif
2825           evdwij=e1+e2
2826 c          write (iout,*) i,j,evdwij
2827           evdw2=evdw2+evdwij
2828           if (calc_grad) then
2829 C
2830 C Calculate contributions to the gradient in the virtual-bond and SC vectors.
2831 C
2832           fac=-(evdwij+e1)*rrij
2833           ggg(1)=xj*fac
2834           ggg(2)=yj*fac
2835           ggg(3)=zj*fac
2836           if (j.lt.i) then
2837 cd          write (iout,*) 'j<i'
2838 C Uncomment following three lines for SC-p interactions
2839 c           do k=1,3
2840 c             gradx_scp(k,j)=gradx_scp(k,j)+ggg(k)
2841 c           enddo
2842           else
2843 cd          write (iout,*) 'j>i'
2844             do k=1,3
2845               ggg(k)=-ggg(k)
2846 C Uncomment following line for SC-p interactions
2847 c             gradx_scp(k,j)=gradx_scp(k,j)-ggg(k)
2848             enddo
2849           endif
2850           do k=1,3
2851             gvdwc_scp(k,i)=gvdwc_scp(k,i)-0.5D0*ggg(k)
2852           enddo
2853           kstart=min0(i+1,j)
2854           kend=max0(i-1,j-1)
2855 cd        write (iout,*) 'i=',i,' j=',j,' kstart=',kstart,' kend=',kend
2856 cd        write (iout,*) ggg(1),ggg(2),ggg(3)
2857           do k=kstart,kend
2858             do l=1,3
2859               gvdwc_scp(l,k)=gvdwc_scp(l,k)-ggg(l)
2860             enddo
2861           enddo
2862           endif
2863         enddo
2864         enddo ! iint
2865  1225   continue
2866       enddo ! i
2867       do i=1,nct
2868         do j=1,3
2869           gvdwc_scp(j,i)=expon*gvdwc_scp(j,i)
2870           gradx_scp(j,i)=expon*gradx_scp(j,i)
2871         enddo
2872       enddo
2873 C******************************************************************************
2874 C
2875 C                              N O T E !!!
2876 C
2877 C To save time the factor EXPON has been extracted from ALL components
2878 C of GVDWC and GRADX. Remember to multiply them by this factor before further 
2879 C use!
2880 C
2881 C******************************************************************************
2882       return
2883       end
2884 C--------------------------------------------------------------------------
2885       subroutine edis(ehpb)
2886
2887 C Evaluate bridge-strain energy and its gradient in virtual-bond and SC vectors.
2888 C
2889       implicit real*8 (a-h,o-z)
2890       include 'DIMENSIONS'
2891       include 'COMMON.SBRIDGE'
2892       include 'COMMON.CHAIN'
2893       include 'COMMON.DERIV'
2894       include 'COMMON.VAR'
2895       include 'COMMON.INTERACT'
2896       include 'COMMON.IOUNITS'
2897       dimension ggg(3)
2898       ehpb=0.0D0
2899 cd      write(iout,*)'edis: nhpb=',nhpb,' fbr=',fbr
2900 cd      write(iout,*)'link_start=',link_start,' link_end=',link_end
2901       if (link_end.eq.0) return
2902       do i=link_start,link_end
2903 C If ihpb(i) and jhpb(i) > NRES, this is a SC-SC distance, otherwise a
2904 C CA-CA distance used in regularization of structure.
2905         ii=ihpb(i)
2906         jj=jhpb(i)
2907 C iii and jjj point to the residues for which the distance is assigned.
2908         if (ii.gt.nres) then
2909           iii=ii-nres
2910           jjj=jj-nres 
2911         else
2912           iii=ii
2913           jjj=jj
2914         endif
2915 c        write (iout,*) "i",i," ii",ii," iii",iii," jj",jj," jjj",jjj,
2916 c     &    dhpb(i),dhpb1(i),forcon(i)
2917 C 24/11/03 AL: SS bridges handled separately because of introducing a specific
2918 C    distance and angle dependent SS bond potential.
2919         if (.not.dyn_ss .and. i.le.nss) then
2920 C 15/02/13 CC dynamic SSbond - additional check
2921         if (ii.gt.nres .and. itype(iii).eq.1 .and. itype(jjj).eq.1) then
2922           call ssbond_ene(iii,jjj,eij)
2923           ehpb=ehpb+2*eij
2924          endif
2925 cd          write (iout,*) "eij",eij
2926         else if (ii.gt.nres .and. jj.gt.nres) then
2927 c Restraints from contact prediction
2928           dd=dist(ii,jj)
2929           if (dhpb1(i).gt.0.0d0) then
2930             ehpb=ehpb+2*forcon(i)*gnmr1(dd,dhpb(i),dhpb1(i))
2931             fac=forcon(i)*gnmr1prim(dd,dhpb(i),dhpb1(i))/dd
2932 c            write (iout,*) "beta nmr",
2933 c     &        dd,2*forcon(i)*gnmr1(dd,dhpb(i),dhpb1(i))
2934           else
2935             dd=dist(ii,jj)
2936             rdis=dd-dhpb(i)
2937 C Get the force constant corresponding to this distance.
2938             waga=forcon(i)
2939 C Calculate the contribution to energy.
2940             ehpb=ehpb+waga*rdis*rdis
2941 c            write (iout,*) "beta reg",dd,waga*rdis*rdis
2942 C
2943 C Evaluate gradient.
2944 C
2945             fac=waga*rdis/dd
2946           endif  
2947           do j=1,3
2948             ggg(j)=fac*(c(j,jj)-c(j,ii))
2949           enddo
2950           do j=1,3
2951             ghpbx(j,iii)=ghpbx(j,iii)-ggg(j)
2952             ghpbx(j,jjj)=ghpbx(j,jjj)+ggg(j)
2953           enddo
2954           do k=1,3
2955             ghpbc(k,jjj)=ghpbc(k,jjj)+ggg(k)
2956             ghpbc(k,iii)=ghpbc(k,iii)-ggg(k)
2957           enddo
2958         else
2959 C Calculate the distance between the two points and its difference from the
2960 C target distance.
2961           dd=dist(ii,jj)
2962           if (dhpb1(i).gt.0.0d0) then
2963             ehpb=ehpb+2*forcon(i)*gnmr1(dd,dhpb(i),dhpb1(i))
2964             fac=forcon(i)*gnmr1prim(dd,dhpb(i),dhpb1(i))/dd
2965 c            write (iout,*) "alph nmr",
2966 c     &        dd,2*forcon(i)*gnmr1(dd,dhpb(i),dhpb1(i))
2967           else
2968             rdis=dd-dhpb(i)
2969 C Get the force constant corresponding to this distance.
2970             waga=forcon(i)
2971 C Calculate the contribution to energy.
2972             ehpb=ehpb+waga*rdis*rdis
2973 c            write (iout,*) "alpha reg",dd,waga*rdis*rdis
2974 C
2975 C Evaluate gradient.
2976 C
2977             fac=waga*rdis/dd
2978           endif
2979 cd      print *,'i=',i,' ii=',ii,' jj=',jj,' dhpb=',dhpb(i),' dd=',dd,
2980 cd   &   ' waga=',waga,' fac=',fac
2981             do j=1,3
2982               ggg(j)=fac*(c(j,jj)-c(j,ii))
2983             enddo
2984 cd      print '(i3,3(1pe14.5))',i,(ggg(j),j=1,3)
2985 C If this is a SC-SC distance, we need to calculate the contributions to the
2986 C Cartesian gradient in the SC vectors (ghpbx).
2987           if (iii.lt.ii) then
2988           do j=1,3
2989             ghpbx(j,iii)=ghpbx(j,iii)-ggg(j)
2990             ghpbx(j,jjj)=ghpbx(j,jjj)+ggg(j)
2991           enddo
2992           endif
2993           do k=1,3
2994             ghpbc(k,jjj)=ghpbc(k,jjj)+ggg(k)
2995             ghpbc(k,iii)=ghpbc(k,iii)-ggg(k)
2996           enddo
2997         endif
2998       enddo
2999       ehpb=0.5D0*ehpb
3000       return
3001       end
3002 C--------------------------------------------------------------------------
3003       subroutine ssbond_ene(i,j,eij)
3004
3005 C Calculate the distance and angle dependent SS-bond potential energy
3006 C using a free-energy function derived based on RHF/6-31G** ab initio
3007 C calculations of diethyl disulfide.
3008 C
3009 C A. Liwo and U. Kozlowska, 11/24/03
3010 C
3011       implicit real*8 (a-h,o-z)
3012       include 'DIMENSIONS'
3013       include 'DIMENSIONS.ZSCOPT'
3014       include 'COMMON.SBRIDGE'
3015       include 'COMMON.CHAIN'
3016       include 'COMMON.DERIV'
3017       include 'COMMON.LOCAL'
3018       include 'COMMON.INTERACT'
3019       include 'COMMON.VAR'
3020       include 'COMMON.IOUNITS'
3021       double precision erij(3),dcosom1(3),dcosom2(3),gg(3)
3022       itypi=itype(i)
3023       xi=c(1,nres+i)
3024       yi=c(2,nres+i)
3025       zi=c(3,nres+i)
3026       dxi=dc_norm(1,nres+i)
3027       dyi=dc_norm(2,nres+i)
3028       dzi=dc_norm(3,nres+i)
3029       dsci_inv=dsc_inv(itypi)
3030       itypj=itype(j)
3031       dscj_inv=dsc_inv(itypj)
3032       xj=c(1,nres+j)-xi
3033       yj=c(2,nres+j)-yi
3034       zj=c(3,nres+j)-zi
3035       dxj=dc_norm(1,nres+j)
3036       dyj=dc_norm(2,nres+j)
3037       dzj=dc_norm(3,nres+j)
3038       rrij=1.0D0/(xj*xj+yj*yj+zj*zj)
3039       rij=dsqrt(rrij)
3040       erij(1)=xj*rij
3041       erij(2)=yj*rij
3042       erij(3)=zj*rij
3043       om1=dxi*erij(1)+dyi*erij(2)+dzi*erij(3)
3044       om2=dxj*erij(1)+dyj*erij(2)+dzj*erij(3)
3045       om12=dxi*dxj+dyi*dyj+dzi*dzj
3046       do k=1,3
3047         dcosom1(k)=rij*(dc_norm(k,nres+i)-om1*erij(k))
3048         dcosom2(k)=rij*(dc_norm(k,nres+j)-om2*erij(k))
3049       enddo
3050       rij=1.0d0/rij
3051       deltad=rij-d0cm
3052       deltat1=1.0d0-om1
3053       deltat2=1.0d0+om2
3054       deltat12=om2-om1+2.0d0
3055       cosphi=om12-om1*om2
3056       eij=akcm*deltad*deltad+akth*(deltat1*deltat1+deltat2*deltat2)
3057      &  +akct*deltad*deltat12+ebr
3058 c     &  +akct*deltad*deltat12
3059      &  +v1ss*cosphi+v2ss*cosphi*cosphi+v3ss*cosphi*cosphi*cosphi
3060       write(iout,*) i,j,"rij",rij,"d0cm",d0cm," akcm",akcm," akth",akth,
3061      &  " akct",akct," deltad",deltad," deltat",deltat1,deltat2,
3062      &  " deltat12",deltat12," eij",eij,"ebr",ebr
3063       ed=2*akcm*deltad+akct*deltat12
3064       pom1=akct*deltad
3065       pom2=v1ss+2*v2ss*cosphi+3*v3ss*cosphi*cosphi
3066       eom1=-2*akth*deltat1-pom1-om2*pom2
3067       eom2= 2*akth*deltat2+pom1-om1*pom2
3068       eom12=pom2
3069       do k=1,3
3070         gg(k)=ed*erij(k)+eom1*dcosom1(k)+eom2*dcosom2(k)
3071       enddo
3072       do k=1,3
3073         ghpbx(k,i)=ghpbx(k,i)-gg(k)
3074      &            +(eom12*dc_norm(k,nres+j)+eom1*erij(k))*dsci_inv
3075         ghpbx(k,j)=ghpbx(k,j)+gg(k)
3076      &            +(eom12*dc_norm(k,nres+i)+eom2*erij(k))*dscj_inv
3077       enddo
3078 C
3079 C Calculate the components of the gradient in DC and X
3080 C
3081       do k=i,j-1
3082         do l=1,3
3083           ghpbc(l,k)=ghpbc(l,k)+gg(l)
3084         enddo
3085       enddo
3086       return
3087       end
3088 C--------------------------------------------------------------------------
3089       subroutine ebond(estr)
3090 c
3091 c Evaluate the energy of stretching of the CA-CA and CA-SC virtual bonds
3092 c
3093       implicit real*8 (a-h,o-z)
3094       include 'DIMENSIONS'
3095       include 'DIMENSIONS.ZSCOPT'
3096       include 'COMMON.LOCAL'
3097       include 'COMMON.GEO'
3098       include 'COMMON.INTERACT'
3099       include 'COMMON.DERIV'
3100       include 'COMMON.VAR'
3101       include 'COMMON.CHAIN'
3102       include 'COMMON.IOUNITS'
3103       include 'COMMON.NAMES'
3104       include 'COMMON.FFIELD'
3105       include 'COMMON.CONTROL'
3106       double precision u(3),ud(3)
3107       logical :: lprn=.false.
3108       estr=0.0d0
3109       do i=nnt+1,nct
3110         diff = vbld(i)-vbldp0
3111 c        write (iout,*) i,vbld(i),vbldp0,diff,AKP*diff*diff
3112         estr=estr+diff*diff
3113         do j=1,3
3114           gradb(j,i-1)=AKP*diff*dc(j,i-1)/vbld(i)
3115         enddo
3116       enddo
3117       estr=0.5d0*AKP*estr
3118 c
3119 c 09/18/07 AL: multimodal bond potential based on AM1 CA-SC PMF's included
3120 c
3121       do i=nnt,nct
3122         iti=itype(i)
3123         if (iti.ne.10) then
3124           nbi=nbondterm(iti)
3125           if (nbi.eq.1) then
3126             diff=vbld(i+nres)-vbldsc0(1,iti)
3127             if (lprn)
3128      &      write (iout,*) i,iti,vbld(i+nres),vbldsc0(1,iti),diff,
3129      &      AKSC(1,iti),AKSC(1,iti)*diff*diff
3130             estr=estr+0.5d0*AKSC(1,iti)*diff*diff
3131             do j=1,3
3132               gradbx(j,i)=AKSC(1,iti)*diff*dc(j,i+nres)/vbld(i+nres)
3133             enddo
3134           else
3135             do j=1,nbi
3136               diff=vbld(i+nres)-vbldsc0(j,iti)
3137               ud(j)=aksc(j,iti)*diff
3138               u(j)=abond0(j,iti)+0.5d0*ud(j)*diff
3139             enddo
3140             uprod=u(1)
3141             do j=2,nbi
3142               uprod=uprod*u(j)
3143             enddo
3144             usum=0.0d0
3145             usumsqder=0.0d0
3146             do j=1,nbi
3147               uprod1=1.0d0
3148               uprod2=1.0d0
3149               do k=1,nbi
3150                 if (k.ne.j) then
3151                   uprod1=uprod1*u(k)
3152                   uprod2=uprod2*u(k)*u(k)
3153                 endif
3154               enddo
3155               usum=usum+uprod1
3156               usumsqder=usumsqder+ud(j)*uprod2
3157             enddo
3158             if (lprn)
3159      &      write (iout,*) i,iti,vbld(i+nres),(vbldsc0(j,iti),
3160      &      AKSC(j,iti),abond0(j,iti),u(j),j=1,nbi)
3161             estr=estr+uprod/usum
3162             do j=1,3
3163              gradbx(j,i)=usumsqder/(usum*usum)*dc(j,i+nres)/vbld(i+nres)
3164             enddo
3165           endif
3166         endif
3167       enddo
3168       return
3169       end
3170 #ifdef CRYST_THETA
3171 C--------------------------------------------------------------------------
3172       subroutine ebend(etheta)
3173 C
3174 C Evaluate the virtual-bond-angle energy given the virtual-bond dihedral
3175 C angles gamma and its derivatives in consecutive thetas and gammas.
3176 C
3177       implicit real*8 (a-h,o-z)
3178       include 'DIMENSIONS'
3179       include 'DIMENSIONS.ZSCOPT'
3180       include 'COMMON.LOCAL'
3181       include 'COMMON.GEO'
3182       include 'COMMON.INTERACT'
3183       include 'COMMON.DERIV'
3184       include 'COMMON.VAR'
3185       include 'COMMON.CHAIN'
3186       include 'COMMON.IOUNITS'
3187       include 'COMMON.NAMES'
3188       include 'COMMON.FFIELD'
3189       common /calcthet/ term1,term2,termm,diffak,ratak,
3190      & ak,aktc,termpre,termexp,sigc,sig0i,time11,time12,sigcsq,
3191      & delthe0,sig0inv,sigtc,sigsqtc,delthec,it
3192       double precision y(2),z(2)
3193       delta=0.02d0*pi
3194       time11=dexp(-2*time)
3195       time12=1.0d0
3196       etheta=0.0D0
3197 c      write (iout,*) "nres",nres
3198 c     write (*,'(a,i2)') 'EBEND ICG=',icg
3199 c      write (iout,*) ithet_start,ithet_end
3200       do i=ithet_start,ithet_end
3201 C Zero the energy function and its derivative at 0 or pi.
3202         call splinthet(theta(i),0.5d0*delta,ss,ssd)
3203         it=itype(i-1)
3204 c        if (i.gt.ithet_start .and. 
3205 c     &     (itel(i-1).eq.0 .or. itel(i-2).eq.0)) goto 1215
3206 c        if (i.gt.3 .and. (i.le.4 .or. itel(i-3).ne.0)) then
3207 c          phii=phi(i)
3208 c          y(1)=dcos(phii)
3209 c          y(2)=dsin(phii)
3210 c        else 
3211 c          y(1)=0.0D0
3212 c          y(2)=0.0D0
3213 c        endif
3214 c        if (i.lt.nres .and. itel(i).ne.0) then
3215 c          phii1=phi(i+1)
3216 c          z(1)=dcos(phii1)
3217 c          z(2)=dsin(phii1)
3218 c        else
3219 c          z(1)=0.0D0
3220 c          z(2)=0.0D0
3221 c        endif  
3222         if (i.gt.3) then
3223 #ifdef OSF
3224           phii=phi(i)
3225           icrc=0
3226           call proc_proc(phii,icrc)
3227           if (icrc.eq.1) phii=150.0
3228 #else
3229           phii=phi(i)
3230 #endif
3231           y(1)=dcos(phii)
3232           y(2)=dsin(phii)
3233         else
3234           y(1)=0.0D0
3235           y(2)=0.0D0
3236         endif
3237         if (i.lt.nres) then
3238 #ifdef OSF
3239           phii1=phi(i+1)
3240           icrc=0
3241           call proc_proc(phii1,icrc)
3242           if (icrc.eq.1) phii1=150.0
3243           phii1=pinorm(phii1)
3244           z(1)=cos(phii1)
3245 #else
3246           phii1=phi(i+1)
3247           z(1)=dcos(phii1)
3248 #endif
3249           z(2)=dsin(phii1)
3250         else
3251           z(1)=0.0D0
3252           z(2)=0.0D0
3253         endif
3254 C Calculate the "mean" value of theta from the part of the distribution
3255 C dependent on the adjacent virtual-bond-valence angles (gamma1 & gamma2).
3256 C In following comments this theta will be referred to as t_c.
3257         thet_pred_mean=0.0d0
3258         do k=1,2
3259           athetk=athet(k,it)
3260           bthetk=bthet(k,it)
3261           thet_pred_mean=thet_pred_mean+athetk*y(k)+bthetk*z(k)
3262         enddo
3263 c        write (iout,*) "thet_pred_mean",thet_pred_mean
3264         dthett=thet_pred_mean*ssd
3265         thet_pred_mean=thet_pred_mean*ss+a0thet(it)
3266 c        write (iout,*) "thet_pred_mean",thet_pred_mean
3267 C Derivatives of the "mean" values in gamma1 and gamma2.
3268         dthetg1=(-athet(1,it)*y(2)+athet(2,it)*y(1))*ss
3269         dthetg2=(-bthet(1,it)*z(2)+bthet(2,it)*z(1))*ss
3270         if (theta(i).gt.pi-delta) then
3271           call theteng(pi-delta,thet_pred_mean,theta0(it),f0,fprim0,
3272      &         E_tc0)
3273           call mixder(pi-delta,thet_pred_mean,theta0(it),fprim_tc0)
3274           call theteng(pi,thet_pred_mean,theta0(it),f1,fprim1,E_tc1)
3275           call spline1(theta(i),pi-delta,delta,f0,f1,fprim0,ethetai,
3276      &        E_theta)
3277           call spline2(theta(i),pi-delta,delta,E_tc0,E_tc1,fprim_tc0,
3278      &        E_tc)
3279         else if (theta(i).lt.delta) then
3280           call theteng(delta,thet_pred_mean,theta0(it),f0,fprim0,E_tc0)
3281           call theteng(0.0d0,thet_pred_mean,theta0(it),f1,fprim1,E_tc1)
3282           call spline1(theta(i),delta,-delta,f0,f1,fprim0,ethetai,
3283      &        E_theta)
3284           call mixder(delta,thet_pred_mean,theta0(it),fprim_tc0)
3285           call spline2(theta(i),delta,-delta,E_tc0,E_tc1,fprim_tc0,
3286      &        E_tc)
3287         else
3288           call theteng(theta(i),thet_pred_mean,theta0(it),ethetai,
3289      &        E_theta,E_tc)
3290         endif
3291         etheta=etheta+ethetai
3292 c        write (iout,'(2i3,3f8.3,f10.5)') i,it,rad2deg*theta(i),
3293 c     &    rad2deg*phii,rad2deg*phii1,ethetai
3294         if (i.gt.3) gloc(i-3,icg)=gloc(i-3,icg)+wang*E_tc*dthetg1
3295         if (i.lt.nres) gloc(i-2,icg)=gloc(i-2,icg)+wang*E_tc*dthetg2
3296         gloc(nphi+i-2,icg)=wang*(E_theta+E_tc*dthett)
3297  1215   continue
3298       enddo
3299 C Ufff.... We've done all this!!! 
3300       return
3301       end
3302 C---------------------------------------------------------------------------
3303       subroutine theteng(thetai,thet_pred_mean,theta0i,ethetai,E_theta,
3304      &     E_tc)
3305       implicit real*8 (a-h,o-z)
3306       include 'DIMENSIONS'
3307       include 'COMMON.LOCAL'
3308       include 'COMMON.IOUNITS'
3309       common /calcthet/ term1,term2,termm,diffak,ratak,
3310      & ak,aktc,termpre,termexp,sigc,sig0i,time11,time12,sigcsq,
3311      & delthe0,sig0inv,sigtc,sigsqtc,delthec,it
3312 C Calculate the contributions to both Gaussian lobes.
3313 C 6/6/97 - Deform the Gaussians using the factor of 1/(1+time)
3314 C The "polynomial part" of the "standard deviation" of this part of 
3315 C the distribution.
3316         sig=polthet(3,it)
3317         do j=2,0,-1
3318           sig=sig*thet_pred_mean+polthet(j,it)
3319         enddo
3320 C Derivative of the "interior part" of the "standard deviation of the" 
3321 C gamma-dependent Gaussian lobe in t_c.
3322         sigtc=3*polthet(3,it)
3323         do j=2,1,-1
3324           sigtc=sigtc*thet_pred_mean+j*polthet(j,it)
3325         enddo
3326         sigtc=sig*sigtc
3327 C Set the parameters of both Gaussian lobes of the distribution.
3328 C "Standard deviation" of the gamma-dependent Gaussian lobe (sigtc)
3329         fac=sig*sig+sigc0(it)
3330         sigcsq=fac+fac
3331         sigc=1.0D0/sigcsq
3332 C Following variable (sigsqtc) is -(1/2)d[sigma(t_c)**(-2))]/dt_c
3333         sigsqtc=-4.0D0*sigcsq*sigtc
3334 c       print *,i,sig,sigtc,sigsqtc
3335 C Following variable (sigtc) is d[sigma(t_c)]/dt_c
3336         sigtc=-sigtc/(fac*fac)
3337 C Following variable is sigma(t_c)**(-2)
3338         sigcsq=sigcsq*sigcsq
3339         sig0i=sig0(it)
3340         sig0inv=1.0D0/sig0i**2
3341         delthec=thetai-thet_pred_mean
3342         delthe0=thetai-theta0i
3343         term1=-0.5D0*sigcsq*delthec*delthec
3344         term2=-0.5D0*sig0inv*delthe0*delthe0
3345 C Following fuzzy logic is to avoid underflows in dexp and subsequent INFs and
3346 C NaNs in taking the logarithm. We extract the largest exponent which is added
3347 C to the energy (this being the log of the distribution) at the end of energy
3348 C term evaluation for this virtual-bond angle.
3349         if (term1.gt.term2) then
3350           termm=term1
3351           term2=dexp(term2-termm)
3352           term1=1.0d0
3353         else
3354           termm=term2
3355           term1=dexp(term1-termm)
3356           term2=1.0d0
3357         endif
3358 C The ratio between the gamma-independent and gamma-dependent lobes of
3359 C the distribution is a Gaussian function of thet_pred_mean too.
3360         diffak=gthet(2,it)-thet_pred_mean
3361         ratak=diffak/gthet(3,it)**2
3362         ak=dexp(gthet(1,it)-0.5D0*diffak*ratak)
3363 C Let's differentiate it in thet_pred_mean NOW.
3364         aktc=ak*ratak
3365 C Now put together the distribution terms to make complete distribution.
3366         termexp=term1+ak*term2
3367         termpre=sigc+ak*sig0i
3368 C Contribution of the bending energy from this theta is just the -log of
3369 C the sum of the contributions from the two lobes and the pre-exponential
3370 C factor. Simple enough, isn't it?
3371         ethetai=(-dlog(termexp)-termm+dlog(termpre))
3372 C NOW the derivatives!!!
3373 C 6/6/97 Take into account the deformation.
3374         E_theta=(delthec*sigcsq*term1
3375      &       +ak*delthe0*sig0inv*term2)/termexp
3376         E_tc=((sigtc+aktc*sig0i)/termpre
3377      &      -((delthec*sigcsq+delthec*delthec*sigsqtc)*term1+
3378      &       aktc*term2)/termexp)
3379       return
3380       end
3381 c-----------------------------------------------------------------------------
3382       subroutine mixder(thetai,thet_pred_mean,theta0i,E_tc_t)
3383       implicit real*8 (a-h,o-z)
3384       include 'DIMENSIONS'
3385       include 'COMMON.LOCAL'
3386       include 'COMMON.IOUNITS'
3387       common /calcthet/ term1,term2,termm,diffak,ratak,
3388      & ak,aktc,termpre,termexp,sigc,sig0i,time11,time12,sigcsq,
3389      & delthe0,sig0inv,sigtc,sigsqtc,delthec,it
3390       delthec=thetai-thet_pred_mean
3391       delthe0=thetai-theta0i
3392 C "Thank you" to MAPLE (probably spared one day of hand-differentiation).
3393       t3 = thetai-thet_pred_mean
3394       t6 = t3**2
3395       t9 = term1
3396       t12 = t3*sigcsq
3397       t14 = t12+t6*sigsqtc
3398       t16 = 1.0d0
3399       t21 = thetai-theta0i
3400       t23 = t21**2
3401       t26 = term2
3402       t27 = t21*t26
3403       t32 = termexp
3404       t40 = t32**2
3405       E_tc_t = -((sigcsq+2.D0*t3*sigsqtc)*t9-t14*sigcsq*t3*t16*t9
3406      & -aktc*sig0inv*t27)/t32+(t14*t9+aktc*t26)/t40
3407      & *(-t12*t9-ak*sig0inv*t27)
3408       return
3409       end
3410 #else
3411 C--------------------------------------------------------------------------
3412       subroutine ebend(etheta)
3413 C
3414 C Evaluate the virtual-bond-angle energy given the virtual-bond dihedral
3415 C angles gamma and its derivatives in consecutive thetas and gammas.
3416 C ab initio-derived potentials from 
3417 c Kozlowska et al., J. Phys.: Condens. Matter 19 (2007) 285203
3418 C
3419       implicit real*8 (a-h,o-z)
3420       include 'DIMENSIONS'
3421       include 'DIMENSIONS.ZSCOPT'
3422       include 'COMMON.LOCAL'
3423       include 'COMMON.GEO'
3424       include 'COMMON.INTERACT'
3425       include 'COMMON.DERIV'
3426       include 'COMMON.VAR'
3427       include 'COMMON.CHAIN'
3428       include 'COMMON.IOUNITS'
3429       include 'COMMON.NAMES'
3430       include 'COMMON.FFIELD'
3431       include 'COMMON.CONTROL'
3432       double precision coskt(mmaxtheterm),sinkt(mmaxtheterm),
3433      & cosph1(maxsingle),sinph1(maxsingle),cosph2(maxsingle),
3434      & sinph2(maxsingle),cosph1ph2(maxdouble,maxdouble),
3435      & sinph1ph2(maxdouble,maxdouble)
3436       logical lprn /.false./, lprn1 /.false./
3437       etheta=0.0D0
3438 c      write (iout,*) "ithetyp",(ithetyp(i),i=1,ntyp1)
3439       do i=ithet_start,ithet_end
3440         dethetai=0.0d0
3441         dephii=0.0d0
3442         dephii1=0.0d0
3443         theti2=0.5d0*theta(i)
3444         ityp2=ithetyp(itype(i-1))
3445         do k=1,nntheterm
3446           coskt(k)=dcos(k*theti2)
3447           sinkt(k)=dsin(k*theti2)
3448         enddo
3449         if (i.gt.3) then
3450 #ifdef OSF
3451           phii=phi(i)
3452           if (phii.ne.phii) phii=150.0
3453 #else
3454           phii=phi(i)
3455 #endif
3456           ityp1=ithetyp(itype(i-2))
3457           do k=1,nsingle
3458             cosph1(k)=dcos(k*phii)
3459             sinph1(k)=dsin(k*phii)
3460           enddo
3461         else
3462           phii=0.0d0
3463           ityp1=nthetyp+1
3464           do k=1,nsingle
3465             cosph1(k)=0.0d0
3466             sinph1(k)=0.0d0
3467           enddo 
3468         endif
3469         if (i.lt.nres) then
3470 #ifdef OSF
3471           phii1=phi(i+1)
3472           if (phii1.ne.phii1) phii1=150.0
3473           phii1=pinorm(phii1)
3474 #else
3475           phii1=phi(i+1)
3476 #endif
3477           ityp3=ithetyp(itype(i))
3478           do k=1,nsingle
3479             cosph2(k)=dcos(k*phii1)
3480             sinph2(k)=dsin(k*phii1)
3481           enddo
3482         else
3483           phii1=0.0d0
3484           ityp3=nthetyp+1
3485           do k=1,nsingle
3486             cosph2(k)=0.0d0
3487             sinph2(k)=0.0d0
3488           enddo
3489         endif  
3490 c        write (iout,*) "i",i," ityp1",itype(i-2),ityp1,
3491 c     &   " ityp2",itype(i-1),ityp2," ityp3",itype(i),ityp3
3492 c        call flush(iout)
3493         ethetai=aa0thet(ityp1,ityp2,ityp3)
3494         do k=1,ndouble
3495           do l=1,k-1
3496             ccl=cosph1(l)*cosph2(k-l)
3497             ssl=sinph1(l)*sinph2(k-l)
3498             scl=sinph1(l)*cosph2(k-l)
3499             csl=cosph1(l)*sinph2(k-l)
3500             cosph1ph2(l,k)=ccl-ssl
3501             cosph1ph2(k,l)=ccl+ssl
3502             sinph1ph2(l,k)=scl+csl
3503             sinph1ph2(k,l)=scl-csl
3504           enddo
3505         enddo
3506         if (lprn) then
3507         write (iout,*) "i",i," ityp1",ityp1," ityp2",ityp2,
3508      &    " ityp3",ityp3," theti2",theti2," phii",phii," phii1",phii1
3509         write (iout,*) "coskt and sinkt"
3510         do k=1,nntheterm
3511           write (iout,*) k,coskt(k),sinkt(k)
3512         enddo
3513         endif
3514         do k=1,ntheterm
3515           ethetai=ethetai+aathet(k,ityp1,ityp2,ityp3)*sinkt(k)
3516           dethetai=dethetai+0.5d0*k*aathet(k,ityp1,ityp2,ityp3)
3517      &      *coskt(k)
3518           if (lprn)
3519      &    write (iout,*) "k",k," aathet",aathet(k,ityp1,ityp2,ityp3),
3520      &     " ethetai",ethetai
3521         enddo
3522         if (lprn) then
3523         write (iout,*) "cosph and sinph"
3524         do k=1,nsingle
3525           write (iout,*) k,cosph1(k),sinph1(k),cosph2(k),sinph2(k)
3526         enddo
3527         write (iout,*) "cosph1ph2 and sinph2ph2"
3528         do k=2,ndouble
3529           do l=1,k-1
3530             write (iout,*) l,k,cosph1ph2(l,k),cosph1ph2(k,l),
3531      &         sinph1ph2(l,k),sinph1ph2(k,l) 
3532           enddo
3533         enddo
3534         write(iout,*) "ethetai",ethetai
3535         endif
3536         do m=1,ntheterm2
3537           do k=1,nsingle
3538             aux=bbthet(k,m,ityp1,ityp2,ityp3)*cosph1(k)
3539      &         +ccthet(k,m,ityp1,ityp2,ityp3)*sinph1(k)
3540      &         +ddthet(k,m,ityp1,ityp2,ityp3)*cosph2(k)
3541      &         +eethet(k,m,ityp1,ityp2,ityp3)*sinph2(k)
3542             ethetai=ethetai+sinkt(m)*aux
3543             dethetai=dethetai+0.5d0*m*aux*coskt(m)
3544             dephii=dephii+k*sinkt(m)*(
3545      &          ccthet(k,m,ityp1,ityp2,ityp3)*cosph1(k)-
3546      &          bbthet(k,m,ityp1,ityp2,ityp3)*sinph1(k))
3547             dephii1=dephii1+k*sinkt(m)*(
3548      &          eethet(k,m,ityp1,ityp2,ityp3)*cosph2(k)-
3549      &          ddthet(k,m,ityp1,ityp2,ityp3)*sinph2(k))
3550             if (lprn)
3551      &      write (iout,*) "m",m," k",k," bbthet",
3552      &         bbthet(k,m,ityp1,ityp2,ityp3)," ccthet",
3553      &         ccthet(k,m,ityp1,ityp2,ityp3)," ddthet",
3554      &         ddthet(k,m,ityp1,ityp2,ityp3)," eethet",
3555      &         eethet(k,m,ityp1,ityp2,ityp3)," ethetai",ethetai
3556           enddo
3557         enddo
3558         if (lprn)
3559      &  write(iout,*) "ethetai",ethetai
3560         do m=1,ntheterm3
3561           do k=2,ndouble
3562             do l=1,k-1
3563               aux=ffthet(l,k,m,ityp1,ityp2,ityp3)*cosph1ph2(l,k)+
3564      &            ffthet(k,l,m,ityp1,ityp2,ityp3)*cosph1ph2(k,l)+
3565      &            ggthet(l,k,m,ityp1,ityp2,ityp3)*sinph1ph2(l,k)+
3566      &            ggthet(k,l,m,ityp1,ityp2,ityp3)*sinph1ph2(k,l)
3567               ethetai=ethetai+sinkt(m)*aux
3568               dethetai=dethetai+0.5d0*m*coskt(m)*aux
3569               dephii=dephii+l*sinkt(m)*(
3570      &           -ffthet(l,k,m,ityp1,ityp2,ityp3)*sinph1ph2(l,k)-
3571      &            ffthet(k,l,m,ityp1,ityp2,ityp3)*sinph1ph2(k,l)+
3572      &            ggthet(l,k,m,ityp1,ityp2,ityp3)*cosph1ph2(l,k)+
3573      &            ggthet(k,l,m,ityp1,ityp2,ityp3)*cosph1ph2(k,l))
3574               dephii1=dephii1+(k-l)*sinkt(m)*(
3575      &           -ffthet(l,k,m,ityp1,ityp2,ityp3)*sinph1ph2(l,k)+
3576      &            ffthet(k,l,m,ityp1,ityp2,ityp3)*sinph1ph2(k,l)+
3577      &            ggthet(l,k,m,ityp1,ityp2,ityp3)*cosph1ph2(l,k)-
3578      &            ggthet(k,l,m,ityp1,ityp2,ityp3)*cosph1ph2(k,l))
3579               if (lprn) then
3580               write (iout,*) "m",m," k",k," l",l," ffthet",
3581      &            ffthet(l,k,m,ityp1,ityp2,ityp3),
3582      &            ffthet(k,l,m,ityp1,ityp2,ityp3)," ggthet",
3583      &            ggthet(l,k,m,ityp1,ityp2,ityp3),
3584      &            ggthet(k,l,m,ityp1,ityp2,ityp3)," ethetai",ethetai
3585               write (iout,*) cosph1ph2(l,k)*sinkt(m),
3586      &            cosph1ph2(k,l)*sinkt(m),
3587      &            sinph1ph2(l,k)*sinkt(m),sinph1ph2(k,l)*sinkt(m)
3588               endif
3589             enddo
3590           enddo
3591         enddo
3592 10      continue
3593 c        lprn1=.true.
3594         if (lprn1) write (iout,'(a4,i2,3f8.1,9h ethetai ,f10.5)') 
3595      &  'ebe',i,theta(i)*rad2deg,phii*rad2deg,
3596      &   phii1*rad2deg,ethetai
3597 c        lprn1=.false.
3598         etheta=etheta+ethetai
3599         
3600         if (i.gt.3) gloc(i-3,icg)=gloc(i-3,icg)+wang*dephii
3601         if (i.lt.nres) gloc(i-2,icg)=gloc(i-2,icg)+wang*dephii1
3602         gloc(nphi+i-2,icg)=wang*dethetai
3603       enddo
3604       return
3605       end
3606 #endif
3607 #ifdef CRYST_SC
3608 c-----------------------------------------------------------------------------
3609       subroutine esc(escloc)
3610 C Calculate the local energy of a side chain and its derivatives in the
3611 C corresponding virtual-bond valence angles THETA and the spherical angles 
3612 C ALPHA and OMEGA.
3613       implicit real*8 (a-h,o-z)
3614       include 'DIMENSIONS'
3615       include 'DIMENSIONS.ZSCOPT'
3616       include 'COMMON.GEO'
3617       include 'COMMON.LOCAL'
3618       include 'COMMON.VAR'
3619       include 'COMMON.INTERACT'
3620       include 'COMMON.DERIV'
3621       include 'COMMON.CHAIN'
3622       include 'COMMON.IOUNITS'
3623       include 'COMMON.NAMES'
3624       include 'COMMON.FFIELD'
3625       double precision x(3),dersc(3),xemp(3),dersc0(3),dersc1(3),
3626      &     ddersc0(3),ddummy(3),xtemp(3),temp(3)
3627       common /sccalc/ time11,time12,time112,theti,it,nlobit
3628       delta=0.02d0*pi
3629       escloc=0.0D0
3630 c     write (iout,'(a)') 'ESC'
3631       do i=loc_start,loc_end
3632         it=itype(i)
3633         if (it.eq.10) goto 1
3634         nlobit=nlob(it)
3635 c       print *,'i=',i,' it=',it,' nlobit=',nlobit
3636 c       write (iout,*) 'i=',i,' ssa=',ssa,' ssad=',ssad
3637         theti=theta(i+1)-pipol
3638         x(1)=dtan(theti)
3639         x(2)=alph(i)
3640         x(3)=omeg(i)
3641 c        write (iout,*) "i",i," x",x(1),x(2),x(3)
3642
3643         if (x(2).gt.pi-delta) then
3644           xtemp(1)=x(1)
3645           xtemp(2)=pi-delta
3646           xtemp(3)=x(3)
3647           call enesc(xtemp,escloci0,dersc0,ddersc0,.true.)
3648           xtemp(2)=pi
3649           call enesc(xtemp,escloci1,dersc1,ddummy,.false.)
3650           call spline1(x(2),pi-delta,delta,escloci0,escloci1,dersc0(2),
3651      &        escloci,dersc(2))
3652           call spline2(x(2),pi-delta,delta,dersc0(1),dersc1(1),
3653      &        ddersc0(1),dersc(1))
3654           call spline2(x(2),pi-delta,delta,dersc0(3),dersc1(3),
3655      &        ddersc0(3),dersc(3))
3656           xtemp(2)=pi-delta
3657           call enesc_bound(xtemp,esclocbi0,dersc0,dersc12,.true.)
3658           xtemp(2)=pi
3659           call enesc_bound(xtemp,esclocbi1,dersc1,chuju,.false.)
3660           call spline1(x(2),pi-delta,delta,esclocbi0,esclocbi1,
3661      &            dersc0(2),esclocbi,dersc02)
3662           call spline2(x(2),pi-delta,delta,dersc0(1),dersc1(1),
3663      &            dersc12,dersc01)
3664           call splinthet(x(2),0.5d0*delta,ss,ssd)
3665           dersc0(1)=dersc01
3666           dersc0(2)=dersc02
3667           dersc0(3)=0.0d0
3668           do k=1,3
3669             dersc(k)=ss*dersc(k)+(1.0d0-ss)*dersc0(k)
3670           enddo
3671           dersc(2)=dersc(2)+ssd*(escloci-esclocbi)
3672 c         write (iout,*) 'i=',i,x(2)*rad2deg,escloci0,escloci,
3673 c    &             esclocbi,ss,ssd
3674           escloci=ss*escloci+(1.0d0-ss)*esclocbi
3675 c         escloci=esclocbi
3676 c         write (iout,*) escloci
3677         else if (x(2).lt.delta) then
3678           xtemp(1)=x(1)
3679           xtemp(2)=delta
3680           xtemp(3)=x(3)
3681           call enesc(xtemp,escloci0,dersc0,ddersc0,.true.)
3682           xtemp(2)=0.0d0
3683           call enesc(xtemp,escloci1,dersc1,ddummy,.false.)
3684           call spline1(x(2),delta,-delta,escloci0,escloci1,dersc0(2),
3685      &        escloci,dersc(2))
3686           call spline2(x(2),delta,-delta,dersc0(1),dersc1(1),
3687      &        ddersc0(1),dersc(1))
3688           call spline2(x(2),delta,-delta,dersc0(3),dersc1(3),
3689      &        ddersc0(3),dersc(3))
3690           xtemp(2)=delta
3691           call enesc_bound(xtemp,esclocbi0,dersc0,dersc12,.true.)
3692           xtemp(2)=0.0d0
3693           call enesc_bound(xtemp,esclocbi1,dersc1,chuju,.false.)
3694           call spline1(x(2),delta,-delta,esclocbi0,esclocbi1,
3695      &            dersc0(2),esclocbi,dersc02)
3696           call spline2(x(2),delta,-delta,dersc0(1),dersc1(1),
3697      &            dersc12,dersc01)
3698           dersc0(1)=dersc01
3699           dersc0(2)=dersc02
3700           dersc0(3)=0.0d0
3701           call splinthet(x(2),0.5d0*delta,ss,ssd)
3702           do k=1,3
3703             dersc(k)=ss*dersc(k)+(1.0d0-ss)*dersc0(k)
3704           enddo
3705           dersc(2)=dersc(2)+ssd*(escloci-esclocbi)
3706 c         write (iout,*) 'i=',i,x(2)*rad2deg,escloci0,escloci,
3707 c    &             esclocbi,ss,ssd
3708           escloci=ss*escloci+(1.0d0-ss)*esclocbi
3709 c         write (iout,*) escloci
3710         else
3711           call enesc(x,escloci,dersc,ddummy,.false.)
3712         endif
3713
3714         escloc=escloc+escloci
3715 c        write (iout,*) 'i=',i,' escloci=',escloci,' dersc=',dersc
3716
3717         gloc(nphi+i-1,icg)=gloc(nphi+i-1,icg)+
3718      &   wscloc*dersc(1)
3719         gloc(ialph(i,1),icg)=wscloc*dersc(2)
3720         gloc(ialph(i,1)+nside,icg)=wscloc*dersc(3)
3721     1   continue
3722       enddo
3723       return
3724       end
3725 C---------------------------------------------------------------------------
3726       subroutine enesc(x,escloci,dersc,ddersc,mixed)
3727       implicit real*8 (a-h,o-z)
3728       include 'DIMENSIONS'
3729       include 'COMMON.GEO'
3730       include 'COMMON.LOCAL'
3731       include 'COMMON.IOUNITS'
3732       common /sccalc/ time11,time12,time112,theti,it,nlobit
3733       double precision x(3),z(3),Ax(3,maxlob,-1:1),dersc(3),ddersc(3)
3734       double precision contr(maxlob,-1:1)
3735       logical mixed
3736 c       write (iout,*) 'it=',it,' nlobit=',nlobit
3737         escloc_i=0.0D0
3738         do j=1,3
3739           dersc(j)=0.0D0
3740           if (mixed) ddersc(j)=0.0d0
3741         enddo
3742         x3=x(3)
3743
3744 C Because of periodicity of the dependence of the SC energy in omega we have
3745 C to add up the contributions from x(3)-2*pi, x(3), and x(3+2*pi).
3746 C To avoid underflows, first compute & store the exponents.
3747
3748         do iii=-1,1
3749
3750           x(3)=x3+iii*dwapi
3751  
3752           do j=1,nlobit
3753             do k=1,3
3754               z(k)=x(k)-censc(k,j,it)
3755             enddo
3756             do k=1,3
3757               Axk=0.0D0
3758               do l=1,3
3759                 Axk=Axk+gaussc(l,k,j,it)*z(l)
3760               enddo
3761               Ax(k,j,iii)=Axk
3762             enddo 
3763             expfac=0.0D0 
3764             do k=1,3
3765               expfac=expfac+Ax(k,j,iii)*z(k)
3766             enddo
3767             contr(j,iii)=expfac
3768           enddo ! j
3769
3770         enddo ! iii
3771
3772         x(3)=x3
3773 C As in the case of ebend, we want to avoid underflows in exponentiation and
3774 C subsequent NaNs and INFs in energy calculation.
3775 C Find the largest exponent
3776         emin=contr(1,-1)
3777         do iii=-1,1
3778           do j=1,nlobit
3779             if (emin.gt.contr(j,iii)) emin=contr(j,iii)
3780           enddo 
3781         enddo
3782         emin=0.5D0*emin
3783 cd      print *,'it=',it,' emin=',emin
3784
3785 C Compute the contribution to SC energy and derivatives
3786         do iii=-1,1
3787
3788           do j=1,nlobit
3789             expfac=dexp(bsc(j,it)-0.5D0*contr(j,iii)+emin)
3790 cd          print *,'j=',j,' expfac=',expfac
3791             escloc_i=escloc_i+expfac
3792             do k=1,3
3793               dersc(k)=dersc(k)+Ax(k,j,iii)*expfac
3794             enddo
3795             if (mixed) then
3796               do k=1,3,2
3797                 ddersc(k)=ddersc(k)+(-Ax(2,j,iii)*Ax(k,j,iii)
3798      &            +gaussc(k,2,j,it))*expfac
3799               enddo
3800             endif
3801           enddo
3802
3803         enddo ! iii
3804
3805         dersc(1)=dersc(1)/cos(theti)**2
3806         ddersc(1)=ddersc(1)/cos(theti)**2
3807         ddersc(3)=ddersc(3)
3808
3809         escloci=-(dlog(escloc_i)-emin)
3810         do j=1,3
3811           dersc(j)=dersc(j)/escloc_i
3812         enddo
3813         if (mixed) then
3814           do j=1,3,2
3815             ddersc(j)=(ddersc(j)/escloc_i+dersc(2)*dersc(j))
3816           enddo
3817         endif
3818       return
3819       end
3820 C------------------------------------------------------------------------------
3821       subroutine enesc_bound(x,escloci,dersc,dersc12,mixed)
3822       implicit real*8 (a-h,o-z)
3823       include 'DIMENSIONS'
3824       include 'COMMON.GEO'
3825       include 'COMMON.LOCAL'
3826       include 'COMMON.IOUNITS'
3827       common /sccalc/ time11,time12,time112,theti,it,nlobit
3828       double precision x(3),z(3),Ax(3,maxlob),dersc(3)
3829       double precision contr(maxlob)
3830       logical mixed
3831
3832       escloc_i=0.0D0
3833
3834       do j=1,3
3835         dersc(j)=0.0D0
3836       enddo
3837
3838       do j=1,nlobit
3839         do k=1,2
3840           z(k)=x(k)-censc(k,j,it)
3841         enddo
3842         z(3)=dwapi
3843         do k=1,3
3844           Axk=0.0D0
3845           do l=1,3
3846             Axk=Axk+gaussc(l,k,j,it)*z(l)
3847           enddo
3848           Ax(k,j)=Axk
3849         enddo 
3850         expfac=0.0D0 
3851         do k=1,3
3852           expfac=expfac+Ax(k,j)*z(k)
3853         enddo
3854         contr(j)=expfac
3855       enddo ! j
3856
3857 C As in the case of ebend, we want to avoid underflows in exponentiation and
3858 C subsequent NaNs and INFs in energy calculation.
3859 C Find the largest exponent
3860       emin=contr(1)
3861       do j=1,nlobit
3862         if (emin.gt.contr(j)) emin=contr(j)
3863       enddo 
3864       emin=0.5D0*emin
3865  
3866 C Compute the contribution to SC energy and derivatives
3867
3868       dersc12=0.0d0
3869       do j=1,nlobit
3870         expfac=dexp(bsc(j,it)-0.5D0*contr(j)+emin)
3871         escloc_i=escloc_i+expfac
3872         do k=1,2
3873           dersc(k)=dersc(k)+Ax(k,j)*expfac
3874         enddo
3875         if (mixed) dersc12=dersc12+(-Ax(2,j)*Ax(1,j)
3876      &            +gaussc(1,2,j,it))*expfac
3877         dersc(3)=0.0d0
3878       enddo
3879
3880       dersc(1)=dersc(1)/cos(theti)**2
3881       dersc12=dersc12/cos(theti)**2
3882       escloci=-(dlog(escloc_i)-emin)
3883       do j=1,2
3884         dersc(j)=dersc(j)/escloc_i
3885       enddo
3886       if (mixed) dersc12=(dersc12/escloc_i+dersc(2)*dersc(1))
3887       return
3888       end
3889 #else
3890 c----------------------------------------------------------------------------------
3891       subroutine esc(escloc)
3892 C Calculate the local energy of a side chain and its derivatives in the
3893 C corresponding virtual-bond valence angles THETA and the spherical angles 
3894 C ALPHA and OMEGA derived from AM1 all-atom calculations.
3895 C added by Urszula Kozlowska. 07/11/2007
3896 C
3897       implicit real*8 (a-h,o-z)
3898       include 'DIMENSIONS'
3899       include 'DIMENSIONS.ZSCOPT'
3900       include 'COMMON.GEO'
3901       include 'COMMON.LOCAL'
3902       include 'COMMON.VAR'
3903       include 'COMMON.SCROT'
3904       include 'COMMON.INTERACT'
3905       include 'COMMON.DERIV'
3906       include 'COMMON.CHAIN'
3907       include 'COMMON.IOUNITS'
3908       include 'COMMON.NAMES'
3909       include 'COMMON.FFIELD'
3910       include 'COMMON.CONTROL'
3911       include 'COMMON.VECTORS'
3912       double precision x_prime(3),y_prime(3),z_prime(3)
3913      &    , sumene,dsc_i,dp2_i,x(65),
3914      &     xx,yy,zz,sumene1,sumene2,sumene3,sumene4,s1,s1_6,s2,s2_6,
3915      &    de_dxx,de_dyy,de_dzz,de_dt
3916       double precision s1_t,s1_6_t,s2_t,s2_6_t
3917       double precision 
3918      & dXX_Ci1(3),dYY_Ci1(3),dZZ_Ci1(3),dXX_Ci(3),
3919      & dYY_Ci(3),dZZ_Ci(3),dXX_XYZ(3),dYY_XYZ(3),dZZ_XYZ(3),
3920      & dt_dCi(3),dt_dCi1(3)
3921       common /sccalc/ time11,time12,time112,theti,it,nlobit
3922       delta=0.02d0*pi
3923       escloc=0.0D0
3924       do i=loc_start,loc_end
3925         costtab(i+1) =dcos(theta(i+1))
3926         sinttab(i+1) =dsqrt(1-costtab(i+1)*costtab(i+1))
3927         cost2tab(i+1)=dsqrt(0.5d0*(1.0d0+costtab(i+1)))
3928         sint2tab(i+1)=dsqrt(0.5d0*(1.0d0-costtab(i+1)))
3929         cosfac2=0.5d0/(1.0d0+costtab(i+1))
3930         cosfac=dsqrt(cosfac2)
3931         sinfac2=0.5d0/(1.0d0-costtab(i+1))
3932         sinfac=dsqrt(sinfac2)
3933         it=itype(i)
3934         if (it.eq.10) goto 1
3935 c
3936 C  Compute the axes of tghe local cartesian coordinates system; store in
3937 c   x_prime, y_prime and z_prime 
3938 c
3939         do j=1,3
3940           x_prime(j) = 0.00
3941           y_prime(j) = 0.00
3942           z_prime(j) = 0.00
3943         enddo
3944 C        write(2,*) "dc_norm", dc_norm(1,i+nres),dc_norm(2,i+nres),
3945 C     &   dc_norm(3,i+nres)
3946         do j = 1,3
3947           x_prime(j) = (dc_norm(j,i) - dc_norm(j,i-1))*cosfac
3948           y_prime(j) = (dc_norm(j,i) + dc_norm(j,i-1))*sinfac
3949         enddo
3950         do j = 1,3
3951           z_prime(j) = -uz(j,i-1)
3952         enddo     
3953 c       write (2,*) "i",i
3954 c       write (2,*) "x_prime",(x_prime(j),j=1,3)
3955 c       write (2,*) "y_prime",(y_prime(j),j=1,3)
3956 c       write (2,*) "z_prime",(z_prime(j),j=1,3)
3957 c       write (2,*) "xx",scalar(x_prime(1),x_prime(1)),
3958 c      & " xy",scalar(x_prime(1),y_prime(1)),
3959 c      & " xz",scalar(x_prime(1),z_prime(1)),
3960 c      & " yy",scalar(y_prime(1),y_prime(1)),
3961 c      & " yz",scalar(y_prime(1),z_prime(1)),
3962 c      & " zz",scalar(z_prime(1),z_prime(1))
3963 c
3964 C Transform the unit vector of the ith side-chain centroid, dC_norm(*,i),
3965 C to local coordinate system. Store in xx, yy, zz.
3966 c
3967         xx=0.0d0
3968         yy=0.0d0
3969         zz=0.0d0
3970         do j = 1,3
3971           xx = xx + x_prime(j)*dc_norm(j,i+nres)
3972           yy = yy + y_prime(j)*dc_norm(j,i+nres)
3973           zz = zz + z_prime(j)*dc_norm(j,i+nres)
3974         enddo
3975
3976         xxtab(i)=xx
3977         yytab(i)=yy
3978         zztab(i)=zz
3979 C
3980 C Compute the energy of the ith side cbain
3981 C
3982 c        write (2,*) "xx",xx," yy",yy," zz",zz
3983         it=itype(i)
3984         do j = 1,65
3985           x(j) = sc_parmin(j,it) 
3986         enddo
3987 #ifdef CHECK_COORD
3988 Cc diagnostics - remove later
3989         xx1 = dcos(alph(2))
3990         yy1 = dsin(alph(2))*dcos(omeg(2))
3991         zz1 = -dsin(alph(2))*dsin(omeg(2))
3992         write(2,'(3f8.1,3f9.3,1x,3f9.3)') 
3993      &    alph(2)*rad2deg,omeg(2)*rad2deg,theta(3)*rad2deg,xx,yy,zz,
3994      &    xx1,yy1,zz1
3995 C,"  --- ", xx_w,yy_w,zz_w
3996 c end diagnostics
3997 #endif
3998         sumene1= x(1)+  x(2)*xx+  x(3)*yy+  x(4)*zz+  x(5)*xx**2
3999      &   + x(6)*yy**2+  x(7)*zz**2+  x(8)*xx*zz+  x(9)*xx*yy
4000      &   + x(10)*yy*zz
4001         sumene2=  x(11) + x(12)*xx + x(13)*yy + x(14)*zz + x(15)*xx**2
4002      & + x(16)*yy**2 + x(17)*zz**2 + x(18)*xx*zz + x(19)*xx*yy
4003      & + x(20)*yy*zz
4004         sumene3=  x(21) +x(22)*xx +x(23)*yy +x(24)*zz +x(25)*xx**2
4005      &  +x(26)*yy**2 +x(27)*zz**2 +x(28)*xx*zz +x(29)*xx*yy
4006      &  +x(30)*yy*zz +x(31)*xx**3 +x(32)*yy**3 +x(33)*zz**3
4007      &  +x(34)*(xx**2)*yy +x(35)*(xx**2)*zz +x(36)*(yy**2)*xx
4008      &  +x(37)*(yy**2)*zz +x(38)*(zz**2)*xx +x(39)*(zz**2)*yy
4009      &  +x(40)*xx*yy*zz
4010         sumene4= x(41) +x(42)*xx +x(43)*yy +x(44)*zz +x(45)*xx**2
4011      &  +x(46)*yy**2 +x(47)*zz**2 +x(48)*xx*zz +x(49)*xx*yy
4012      &  +x(50)*yy*zz +x(51)*xx**3 +x(52)*yy**3 +x(53)*zz**3
4013      &  +x(54)*(xx**2)*yy +x(55)*(xx**2)*zz +x(56)*(yy**2)*xx
4014      &  +x(57)*(yy**2)*zz +x(58)*(zz**2)*xx +x(59)*(zz**2)*yy
4015      &  +x(60)*xx*yy*zz
4016         dsc_i   = 0.743d0+x(61)
4017         dp2_i   = 1.9d0+x(62)
4018         dscp1=dsqrt(dsc_i**2+dp2_i**2-2*dsc_i*dp2_i
4019      &          *(xx*cost2tab(i+1)+yy*sint2tab(i+1)))
4020         dscp2=dsqrt(dsc_i**2+dp2_i**2-2*dsc_i*dp2_i
4021      &          *(xx*cost2tab(i+1)-yy*sint2tab(i+1)))
4022         s1=(1+x(63))/(0.1d0 + dscp1)
4023         s1_6=(1+x(64))/(0.1d0 + dscp1**6)
4024         s2=(1+x(65))/(0.1d0 + dscp2)
4025         s2_6=(1+x(65))/(0.1d0 + dscp2**6)
4026         sumene = ( sumene3*sint2tab(i+1) + sumene1)*(s1+s1_6)
4027      & + (sumene4*cost2tab(i+1) +sumene2)*(s2+s2_6)
4028 c        write(2,'(i2," sumene",7f9.3)') i,sumene1,sumene2,sumene3,
4029 c     &   sumene4,
4030 c     &   dscp1,dscp2,sumene
4031 c        sumene = enesc(x,xx,yy,zz,cost2tab(i+1),sint2tab(i+1))
4032         escloc = escloc + sumene
4033 c        write (2,*) "escloc",escloc
4034         if (.not. calc_grad) goto 1
4035
4036 #ifdef DEBUG2
4037 C
4038 C This section to check the numerical derivatives of the energy of ith side
4039 C chain in xx, yy, zz, and theta. Use the -DDEBUG compiler option or insert
4040 C #define DEBUG in the code to turn it on.
4041 C
4042         write (2,*) "sumene               =",sumene
4043         aincr=1.0d-7
4044         xxsave=xx
4045         xx=xx+aincr
4046         write (2,*) xx,yy,zz
4047         sumenep = enesc(x,xx,yy,zz,cost2tab(i+1),sint2tab(i+1))
4048         de_dxx_num=(sumenep-sumene)/aincr
4049         xx=xxsave
4050         write (2,*) "xx+ sumene from enesc=",sumenep
4051         yysave=yy
4052         yy=yy+aincr
4053         write (2,*) xx,yy,zz
4054         sumenep = enesc(x,xx,yy,zz,cost2tab(i+1),sint2tab(i+1))
4055         de_dyy_num=(sumenep-sumene)/aincr
4056         yy=yysave
4057         write (2,*) "yy+ sumene from enesc=",sumenep
4058         zzsave=zz
4059         zz=zz+aincr
4060         write (2,*) xx,yy,zz
4061         sumenep = enesc(x,xx,yy,zz,cost2tab(i+1),sint2tab(i+1))
4062         de_dzz_num=(sumenep-sumene)/aincr
4063         zz=zzsave
4064         write (2,*) "zz+ sumene from enesc=",sumenep
4065         costsave=cost2tab(i+1)
4066         sintsave=sint2tab(i+1)
4067         cost2tab(i+1)=dcos(0.5d0*(theta(i+1)+aincr))
4068         sint2tab(i+1)=dsin(0.5d0*(theta(i+1)+aincr))
4069         sumenep = enesc(x,xx,yy,zz,cost2tab(i+1),sint2tab(i+1))
4070         de_dt_num=(sumenep-sumene)/aincr
4071         write (2,*) " t+ sumene from enesc=",sumenep
4072         cost2tab(i+1)=costsave
4073         sint2tab(i+1)=sintsave
4074 C End of diagnostics section.
4075 #endif
4076 C        
4077 C Compute the gradient of esc
4078 C
4079         pom_s1=(1.0d0+x(63))/(0.1d0 + dscp1)**2
4080         pom_s16=6*(1.0d0+x(64))/(0.1d0 + dscp1**6)**2
4081         pom_s2=(1.0d0+x(65))/(0.1d0 + dscp2)**2
4082         pom_s26=6*(1.0d0+x(65))/(0.1d0 + dscp2**6)**2
4083         pom_dx=dsc_i*dp2_i*cost2tab(i+1)
4084         pom_dy=dsc_i*dp2_i*sint2tab(i+1)
4085         pom_dt1=-0.5d0*dsc_i*dp2_i*(xx*sint2tab(i+1)-yy*cost2tab(i+1))
4086         pom_dt2=-0.5d0*dsc_i*dp2_i*(xx*sint2tab(i+1)+yy*cost2tab(i+1))
4087         pom1=(sumene3*sint2tab(i+1)+sumene1)
4088      &     *(pom_s1/dscp1+pom_s16*dscp1**4)
4089         pom2=(sumene4*cost2tab(i+1)+sumene2)
4090      &     *(pom_s2/dscp2+pom_s26*dscp2**4)
4091         sumene1x=x(2)+2*x(5)*xx+x(8)*zz+ x(9)*yy
4092         sumene3x=x(22)+2*x(25)*xx+x(28)*zz+x(29)*yy+3*x(31)*xx**2
4093      &  +2*x(34)*xx*yy +2*x(35)*xx*zz +x(36)*(yy**2) +x(38)*(zz**2)
4094      &  +x(40)*yy*zz
4095         sumene2x=x(12)+2*x(15)*xx+x(18)*zz+ x(19)*yy
4096         sumene4x=x(42)+2*x(45)*xx +x(48)*zz +x(49)*yy +3*x(51)*xx**2
4097      &  +2*x(54)*xx*yy+2*x(55)*xx*zz+x(56)*(yy**2)+x(58)*(zz**2)
4098      &  +x(60)*yy*zz
4099         de_dxx =(sumene1x+sumene3x*sint2tab(i+1))*(s1+s1_6)
4100      &        +(sumene2x+sumene4x*cost2tab(i+1))*(s2+s2_6)
4101      &        +(pom1+pom2)*pom_dx
4102 #ifdef DEBUG
4103         write(2,*), "de_dxx = ", de_dxx,de_dxx_num
4104 #endif
4105 C
4106         sumene1y=x(3) + 2*x(6)*yy + x(9)*xx + x(10)*zz
4107         sumene3y=x(23) +2*x(26)*yy +x(29)*xx +x(30)*zz +3*x(32)*yy**2
4108      &  +x(34)*(xx**2) +2*x(36)*yy*xx +2*x(37)*yy*zz +x(39)*(zz**2)
4109      &  +x(40)*xx*zz
4110         sumene2y=x(13) + 2*x(16)*yy + x(19)*xx + x(20)*zz
4111         sumene4y=x(43)+2*x(46)*yy+x(49)*xx +x(50)*zz
4112      &  +3*x(52)*yy**2+x(54)*xx**2+2*x(56)*yy*xx +2*x(57)*yy*zz
4113      &  +x(59)*zz**2 +x(60)*xx*zz
4114         de_dyy =(sumene1y+sumene3y*sint2tab(i+1))*(s1+s1_6)
4115      &        +(sumene2y+sumene4y*cost2tab(i+1))*(s2+s2_6)
4116      &        +(pom1-pom2)*pom_dy
4117 #ifdef DEBUG
4118         write(2,*), "de_dyy = ", de_dyy,de_dyy_num
4119 #endif
4120 C
4121         de_dzz =(x(24) +2*x(27)*zz +x(28)*xx +x(30)*yy
4122      &  +3*x(33)*zz**2 +x(35)*xx**2 +x(37)*yy**2 +2*x(38)*zz*xx 
4123      &  +2*x(39)*zz*yy +x(40)*xx*yy)*sint2tab(i+1)*(s1+s1_6) 
4124      &  +(x(4) + 2*x(7)*zz+  x(8)*xx + x(10)*yy)*(s1+s1_6) 
4125      &  +(x(44)+2*x(47)*zz +x(48)*xx   +x(50)*yy  +3*x(53)*zz**2   
4126      &  +x(55)*xx**2 +x(57)*(yy**2)+2*x(58)*zz*xx +2*x(59)*zz*yy  
4127      &  +x(60)*xx*yy)*cost2tab(i+1)*(s2+s2_6)
4128      &  + ( x(14) + 2*x(17)*zz+  x(18)*xx + x(20)*yy)*(s2+s2_6)
4129 #ifdef DEBUG
4130         write(2,*), "de_dzz = ", de_dzz,de_dzz_num
4131 #endif
4132 C
4133         de_dt =  0.5d0*sumene3*cost2tab(i+1)*(s1+s1_6) 
4134      &  -0.5d0*sumene4*sint2tab(i+1)*(s2+s2_6)
4135      &  +pom1*pom_dt1+pom2*pom_dt2
4136 #ifdef DEBUG
4137         write(2,*), "de_dt = ", de_dt,de_dt_num
4138 #endif
4139
4140 C
4141        cossc=scalar(dc_norm(1,i),dc_norm(1,i+nres))
4142        cossc1=scalar(dc_norm(1,i-1),dc_norm(1,i+nres))
4143        cosfac2xx=cosfac2*xx
4144        sinfac2yy=sinfac2*yy
4145        do k = 1,3
4146          dt_dCi(k) = -(dc_norm(k,i-1)+costtab(i+1)*dc_norm(k,i))*
4147      &      vbld_inv(i+1)
4148          dt_dCi1(k)= -(dc_norm(k,i)+costtab(i+1)*dc_norm(k,i-1))*
4149      &      vbld_inv(i)
4150          pom=(dC_norm(k,i+nres)-cossc*dC_norm(k,i))*vbld_inv(i+1)
4151          pom1=(dC_norm(k,i+nres)-cossc1*dC_norm(k,i-1))*vbld_inv(i)
4152 c         write (iout,*) "i",i," k",k," pom",pom," pom1",pom1,
4153 c     &    " dt_dCi",dt_dCi(k)," dt_dCi1",dt_dCi1(k)
4154 c         write (iout,*) "dC_norm",(dC_norm(j,i),j=1,3),
4155 c     &   (dC_norm(j,i-1),j=1,3)," vbld_inv",vbld_inv(i+1),vbld_inv(i)
4156          dXX_Ci(k)=pom*cosfac-dt_dCi(k)*cosfac2xx
4157          dXX_Ci1(k)=-pom1*cosfac-dt_dCi1(k)*cosfac2xx
4158          dYY_Ci(k)=pom*sinfac+dt_dCi(k)*sinfac2yy
4159          dYY_Ci1(k)=pom1*sinfac+dt_dCi1(k)*sinfac2yy
4160          dZZ_Ci1(k)=0.0d0
4161          dZZ_Ci(k)=0.0d0
4162          do j=1,3
4163            dZZ_Ci(k)=dZZ_Ci(k)-uzgrad(j,k,2,i-1)*dC_norm(j,i+nres)
4164            dZZ_Ci1(k)=dZZ_Ci1(k)-uzgrad(j,k,1,i-1)*dC_norm(j,i+nres)
4165          enddo
4166           
4167          dXX_XYZ(k)=vbld_inv(i+nres)*(x_prime(k)-xx*dC_norm(k,i+nres))
4168          dYY_XYZ(k)=vbld_inv(i+nres)*(y_prime(k)-yy*dC_norm(k,i+nres))
4169          dZZ_XYZ(k)=vbld_inv(i+nres)*(z_prime(k)-zz*dC_norm(k,i+nres))
4170 c
4171          dt_dCi(k) = -dt_dCi(k)/sinttab(i+1)
4172          dt_dCi1(k)= -dt_dCi1(k)/sinttab(i+1)
4173        enddo
4174
4175        do k=1,3
4176          dXX_Ctab(k,i)=dXX_Ci(k)
4177          dXX_C1tab(k,i)=dXX_Ci1(k)
4178          dYY_Ctab(k,i)=dYY_Ci(k)
4179          dYY_C1tab(k,i)=dYY_Ci1(k)
4180          dZZ_Ctab(k,i)=dZZ_Ci(k)
4181          dZZ_C1tab(k,i)=dZZ_Ci1(k)
4182          dXX_XYZtab(k,i)=dXX_XYZ(k)
4183          dYY_XYZtab(k,i)=dYY_XYZ(k)
4184          dZZ_XYZtab(k,i)=dZZ_XYZ(k)
4185        enddo
4186
4187        do k = 1,3
4188 c         write (iout,*) "k",k," dxx_ci1",dxx_ci1(k)," dyy_ci1",
4189 c     &    dyy_ci1(k)," dzz_ci1",dzz_ci1(k)
4190 c         write (iout,*) "k",k," dxx_ci",dxx_ci(k)," dyy_ci",
4191 c     &    dyy_ci(k)," dzz_ci",dzz_ci(k)
4192 c         write (iout,*) "k",k," dt_dci",dt_dci(k)," dt_dci",
4193 c     &    dt_dci(k)
4194 c         write (iout,*) "k",k," dxx_XYZ",dxx_XYZ(k)," dyy_XYZ",
4195 c     &    dyy_XYZ(k)," dzz_XYZ",dzz_XYZ(k) 
4196          gscloc(k,i-1)=gscloc(k,i-1)+de_dxx*dxx_ci1(k)
4197      &    +de_dyy*dyy_ci1(k)+de_dzz*dzz_ci1(k)+de_dt*dt_dCi1(k)
4198          gscloc(k,i)=gscloc(k,i)+de_dxx*dxx_Ci(k)
4199      &    +de_dyy*dyy_Ci(k)+de_dzz*dzz_Ci(k)+de_dt*dt_dCi(k)
4200          gsclocx(k,i)=                 de_dxx*dxx_XYZ(k)
4201      &    +de_dyy*dyy_XYZ(k)+de_dzz*dzz_XYZ(k)
4202        enddo
4203 c       write(iout,*) "ENERGY GRAD = ", (gscloc(k,i-1),k=1,3),
4204 c     &  (gscloc(k,i),k=1,3),(gsclocx(k,i),k=1,3)  
4205
4206 C to check gradient call subroutine check_grad
4207
4208     1 continue
4209       enddo
4210       return
4211       end
4212 #endif
4213 c------------------------------------------------------------------------------
4214       subroutine gcont(rij,r0ij,eps0ij,delta,fcont,fprimcont)
4215 C
4216 C This procedure calculates two-body contact function g(rij) and its derivative:
4217 C
4218 C           eps0ij                                     !       x < -1
4219 C g(rij) =  esp0ij*(-0.9375*x+0.625*x**3-0.1875*x**5)  ! -1 =< x =< 1
4220 C            0                                         !       x > 1
4221 C
4222 C where x=(rij-r0ij)/delta
4223 C
4224 C rij - interbody distance, r0ij - contact distance, eps0ij - contact energy
4225 C
4226       implicit none
4227       double precision rij,r0ij,eps0ij,fcont,fprimcont
4228       double precision x,x2,x4,delta
4229 c     delta=0.02D0*r0ij
4230 c      delta=0.2D0*r0ij
4231       x=(rij-r0ij)/delta
4232       if (x.lt.-1.0D0) then
4233         fcont=eps0ij
4234         fprimcont=0.0D0
4235       else if (x.le.1.0D0) then  
4236         x2=x*x
4237         x4=x2*x2
4238         fcont=eps0ij*(x*(-0.9375D0+0.6250D0*x2-0.1875D0*x4)+0.5D0)
4239         fprimcont=eps0ij * (-0.9375D0+1.8750D0*x2-0.9375D0*x4)/delta
4240       else
4241         fcont=0.0D0
4242         fprimcont=0.0D0
4243       endif
4244       return
4245       end
4246 c------------------------------------------------------------------------------
4247       subroutine splinthet(theti,delta,ss,ssder)
4248       implicit real*8 (a-h,o-z)
4249       include 'DIMENSIONS'
4250       include 'DIMENSIONS.ZSCOPT'
4251       include 'COMMON.VAR'
4252       include 'COMMON.GEO'
4253       thetup=pi-delta
4254       thetlow=delta
4255       if (theti.gt.pipol) then
4256         call gcont(theti,thetup,1.0d0,delta,ss,ssder)
4257       else
4258         call gcont(-theti,-thetlow,1.0d0,delta,ss,ssder)
4259         ssder=-ssder
4260       endif
4261       return
4262       end
4263 c------------------------------------------------------------------------------
4264       subroutine spline1(x,x0,delta,f0,f1,fprim0,f,fprim)
4265       implicit none
4266       double precision x,x0,delta,f0,f1,fprim0,f,fprim
4267       double precision ksi,ksi2,ksi3,a1,a2,a3
4268       a1=fprim0*delta/(f1-f0)
4269       a2=3.0d0-2.0d0*a1
4270       a3=a1-2.0d0
4271       ksi=(x-x0)/delta
4272       ksi2=ksi*ksi
4273       ksi3=ksi2*ksi  
4274       f=f0+(f1-f0)*ksi*(a1+ksi*(a2+a3*ksi))
4275       fprim=(f1-f0)/delta*(a1+ksi*(2*a2+3*ksi*a3))
4276       return
4277       end
4278 c------------------------------------------------------------------------------
4279       subroutine spline2(x,x0,delta,f0x,f1x,fprim0x,fx)
4280       implicit none
4281       double precision x,x0,delta,f0x,f1x,fprim0x,fx
4282       double precision ksi,ksi2,ksi3,a1,a2,a3
4283       ksi=(x-x0)/delta  
4284       ksi2=ksi*ksi
4285       ksi3=ksi2*ksi
4286       a1=fprim0x*delta
4287       a2=3*(f1x-f0x)-2*fprim0x*delta
4288       a3=fprim0x*delta-2*(f1x-f0x)
4289       fx=f0x+a1*ksi+a2*ksi2+a3*ksi3
4290       return
4291       end
4292 C-----------------------------------------------------------------------------
4293 #ifdef CRYST_TOR
4294 C-----------------------------------------------------------------------------
4295       subroutine etor(etors,edihcnstr,fact)
4296       implicit real*8 (a-h,o-z)
4297       include 'DIMENSIONS'
4298       include 'DIMENSIONS.ZSCOPT'
4299       include 'COMMON.VAR'
4300       include 'COMMON.GEO'
4301       include 'COMMON.LOCAL'
4302       include 'COMMON.TORSION'
4303       include 'COMMON.INTERACT'
4304       include 'COMMON.DERIV'
4305       include 'COMMON.CHAIN'
4306       include 'COMMON.NAMES'
4307       include 'COMMON.IOUNITS'
4308       include 'COMMON.FFIELD'
4309       include 'COMMON.TORCNSTR'
4310       logical lprn
4311 C Set lprn=.true. for debugging
4312       lprn=.false.
4313 c      lprn=.true.
4314       etors=0.0D0
4315       do i=iphi_start,iphi_end
4316         itori=itortyp(itype(i-2))
4317         itori1=itortyp(itype(i-1))
4318         phii=phi(i)
4319         gloci=0.0D0
4320 C Proline-Proline pair is a special case...
4321         if (itori.eq.3 .and. itori1.eq.3) then
4322           if (phii.gt.-dwapi3) then
4323             cosphi=dcos(3*phii)
4324             fac=1.0D0/(1.0D0-cosphi)
4325             etorsi=v1(1,3,3)*fac
4326             etorsi=etorsi+etorsi
4327             etors=etors+etorsi-v1(1,3,3)
4328             gloci=gloci-3*fac*etorsi*dsin(3*phii)
4329           endif
4330           do j=1,3
4331             v1ij=v1(j+1,itori,itori1)
4332             v2ij=v2(j+1,itori,itori1)
4333             cosphi=dcos(j*phii)
4334             sinphi=dsin(j*phii)
4335             etors=etors+v1ij*cosphi+v2ij*sinphi+dabs(v1ij)+dabs(v2ij)
4336             gloci=gloci+j*(v2ij*cosphi-v1ij*sinphi)
4337           enddo
4338         else 
4339           do j=1,nterm_old
4340             v1ij=v1(j,itori,itori1)
4341             v2ij=v2(j,itori,itori1)
4342             cosphi=dcos(j*phii)
4343             sinphi=dsin(j*phii)
4344             etors=etors+v1ij*cosphi+v2ij*sinphi+dabs(v1ij)+dabs(v2ij)
4345             gloci=gloci+j*(v2ij*cosphi-v1ij*sinphi)
4346           enddo
4347         endif
4348         if (lprn)
4349      &  write (iout,'(2(a3,2x,i3,2x),2i3,6f8.3/26x,6f8.3/)')
4350      &  restyp(itype(i-2)),i-2,restyp(itype(i-1)),i-1,itori,itori1,
4351      &  (v1(j,itori,itori1),j=1,6),(v2(j,itori,itori1),j=1,6)
4352         gloc(i-3,icg)=gloc(i-3,icg)+wtor*fact*gloci
4353 c       write (iout,*) 'i=',i,' gloc=',gloc(i-3,icg)
4354       enddo
4355 ! 6/20/98 - dihedral angle constraints
4356       edihcnstr=0.0d0
4357       do i=1,ndih_constr
4358         itori=idih_constr(i)
4359         phii=phi(itori)
4360         difi=phii-phi0(i)
4361         if (difi.gt.drange(i)) then
4362           difi=difi-drange(i)
4363           edihcnstr=edihcnstr+0.25d0*ftors*difi**4
4364           gloc(itori-3,icg)=gloc(itori-3,icg)+ftors*difi**3
4365         else if (difi.lt.-drange(i)) then
4366           difi=difi+drange(i)
4367           edihcnstr=edihcnstr+0.25d0*ftors*difi**4
4368           gloc(itori-3,icg)=gloc(itori-3,icg)+ftors*difi**3
4369         endif
4370 !        write (iout,'(2i5,2f8.3,2e14.5)') i,itori,rad2deg*phii,
4371 !     &    rad2deg*difi,0.25d0*ftors*difi**4,gloc(itori-3,icg)
4372       enddo
4373 !      write (iout,*) 'edihcnstr',edihcnstr
4374       return
4375       end
4376 c------------------------------------------------------------------------------
4377 #else
4378       subroutine etor(etors,edihcnstr,fact)
4379       implicit real*8 (a-h,o-z)
4380       include 'DIMENSIONS'
4381       include 'DIMENSIONS.ZSCOPT'
4382       include 'COMMON.VAR'
4383       include 'COMMON.GEO'
4384       include 'COMMON.LOCAL'
4385       include 'COMMON.TORSION'
4386       include 'COMMON.INTERACT'
4387       include 'COMMON.DERIV'
4388       include 'COMMON.CHAIN'
4389       include 'COMMON.NAMES'
4390       include 'COMMON.IOUNITS'
4391       include 'COMMON.FFIELD'
4392       include 'COMMON.TORCNSTR'
4393       logical lprn
4394 C Set lprn=.true. for debugging
4395       lprn=.false.
4396 c      lprn=.true.
4397       etors=0.0D0
4398       do i=iphi_start,iphi_end
4399         if (itel(i-2).eq.0 .or. itel(i-1).eq.0) goto 1215
4400         itori=itortyp(itype(i-2))
4401         itori1=itortyp(itype(i-1))
4402         phii=phi(i)
4403         gloci=0.0D0
4404 C Regular cosine and sine terms
4405         do j=1,nterm(itori,itori1)
4406           v1ij=v1(j,itori,itori1)
4407           v2ij=v2(j,itori,itori1)
4408           cosphi=dcos(j*phii)
4409           sinphi=dsin(j*phii)
4410           etors=etors+v1ij*cosphi+v2ij*sinphi
4411           gloci=gloci+j*(v2ij*cosphi-v1ij*sinphi)
4412         enddo
4413 C Lorentz terms
4414 C                         v1
4415 C  E = SUM ----------------------------------- - v1
4416 C          [v2 cos(phi/2)+v3 sin(phi/2)]^2 + 1
4417 C
4418         cosphi=dcos(0.5d0*phii)
4419         sinphi=dsin(0.5d0*phii)
4420         do j=1,nlor(itori,itori1)
4421           vl1ij=vlor1(j,itori,itori1)
4422           vl2ij=vlor2(j,itori,itori1)
4423           vl3ij=vlor3(j,itori,itori1)
4424           pom=vl2ij*cosphi+vl3ij*sinphi
4425           pom1=1.0d0/(pom*pom+1.0d0)
4426           etors=etors+vl1ij*pom1
4427           pom=-pom*pom1*pom1
4428           gloci=gloci+vl1ij*(vl3ij*cosphi-vl2ij*sinphi)*pom
4429         enddo
4430 C Subtract the constant term
4431         etors=etors-v0(itori,itori1)
4432         if (lprn)
4433      &  write (iout,'(2(a3,2x,i3,2x),2i3,6f8.3/26x,6f8.3/)')
4434      &  restyp(itype(i-2)),i-2,restyp(itype(i-1)),i-1,itori,itori1,
4435      &  (v1(j,itori,itori1),j=1,6),(v2(j,itori,itori1),j=1,6)
4436         gloc(i-3,icg)=gloc(i-3,icg)+wtor*fact*gloci
4437 c       write (iout,*) 'i=',i,' gloc=',gloc(i-3,icg)
4438  1215   continue
4439       enddo
4440 ! 6/20/98 - dihedral angle constraints
4441       edihcnstr=0.0d0
4442       do i=1,ndih_constr
4443         itori=idih_constr(i)
4444         phii=phi(itori)
4445         difi=pinorm(phii-phi0(i))
4446         edihi=0.0d0
4447         if (difi.gt.drange(i)) then
4448           difi=difi-drange(i)
4449           edihcnstr=edihcnstr+0.25d0*ftors*difi**4
4450           gloc(itori-3,icg)=gloc(itori-3,icg)+ftors*difi**3
4451           edihi=0.25d0*ftors*difi**4
4452         else if (difi.lt.-drange(i)) then
4453           difi=difi+drange(i)
4454           edihcnstr=edihcnstr+0.25d0*ftors*difi**4
4455           gloc(itori-3,icg)=gloc(itori-3,icg)+ftors*difi**3
4456           edihi=0.25d0*ftors*difi**4
4457         else
4458           difi=0.0d0
4459         endif
4460 c        write (iout,'(2i5,4f10.5,e15.5)') i,itori,phii,phi0(i),difi,
4461 c     &    drange(i),edihi
4462 !        write (iout,'(2i5,2f8.3,2e14.5)') i,itori,rad2deg*phii,
4463 !     &    rad2deg*difi,0.25d0*ftors*difi**4,gloc(itori-3,icg)
4464       enddo
4465 !      write (iout,*) 'edihcnstr',edihcnstr
4466       return
4467       end
4468 c----------------------------------------------------------------------------
4469       subroutine etor_d(etors_d,fact2)
4470 C 6/23/01 Compute double torsional energy
4471       implicit real*8 (a-h,o-z)
4472       include 'DIMENSIONS'
4473       include 'DIMENSIONS.ZSCOPT'
4474       include 'COMMON.VAR'
4475       include 'COMMON.GEO'
4476       include 'COMMON.LOCAL'
4477       include 'COMMON.TORSION'
4478       include 'COMMON.INTERACT'
4479       include 'COMMON.DERIV'
4480       include 'COMMON.CHAIN'
4481       include 'COMMON.NAMES'
4482       include 'COMMON.IOUNITS'
4483       include 'COMMON.FFIELD'
4484       include 'COMMON.TORCNSTR'
4485       logical lprn
4486 C Set lprn=.true. for debugging
4487       lprn=.false.
4488 c     lprn=.true.
4489       etors_d=0.0D0
4490       do i=iphi_start,iphi_end-1
4491         if (itel(i-2).eq.0 .or. itel(i-1).eq.0 .or. itel(i).eq.0) 
4492      &     goto 1215
4493         itori=itortyp(itype(i-2))
4494         itori1=itortyp(itype(i-1))
4495         itori2=itortyp(itype(i))
4496         phii=phi(i)
4497         phii1=phi(i+1)
4498         gloci1=0.0D0
4499         gloci2=0.0D0
4500 C Regular cosine and sine terms
4501         do j=1,ntermd_1(itori,itori1,itori2)
4502           v1cij=v1c(1,j,itori,itori1,itori2)
4503           v1sij=v1s(1,j,itori,itori1,itori2)
4504           v2cij=v1c(2,j,itori,itori1,itori2)
4505           v2sij=v1s(2,j,itori,itori1,itori2)
4506           cosphi1=dcos(j*phii)
4507           sinphi1=dsin(j*phii)
4508           cosphi2=dcos(j*phii1)
4509           sinphi2=dsin(j*phii1)
4510           etors_d=etors_d+v1cij*cosphi1+v1sij*sinphi1+
4511      &     v2cij*cosphi2+v2sij*sinphi2
4512           gloci1=gloci1+j*(v1sij*cosphi1-v1cij*sinphi1)
4513           gloci2=gloci2+j*(v2sij*cosphi2-v2cij*sinphi2)
4514         enddo
4515         do k=2,ntermd_2(itori,itori1,itori2)
4516           do l=1,k-1
4517             v1cdij = v2c(k,l,itori,itori1,itori2)
4518             v2cdij = v2c(l,k,itori,itori1,itori2)
4519             v1sdij = v2s(k,l,itori,itori1,itori2)
4520             v2sdij = v2s(l,k,itori,itori1,itori2)
4521             cosphi1p2=dcos(l*phii+(k-l)*phii1)
4522             cosphi1m2=dcos(l*phii-(k-l)*phii1)
4523             sinphi1p2=dsin(l*phii+(k-l)*phii1)
4524             sinphi1m2=dsin(l*phii-(k-l)*phii1)
4525             etors_d=etors_d+v1cdij*cosphi1p2+v2cdij*cosphi1m2+
4526      &        v1sdij*sinphi1p2+v2sdij*sinphi1m2
4527             gloci1=gloci1+l*(v1sdij*cosphi1p2+v2sdij*cosphi1m2
4528      &        -v1cdij*sinphi1p2-v2cdij*sinphi1m2)
4529             gloci2=gloci2+(k-l)*(v1sdij*cosphi1p2-v2sdij*cosphi1m2
4530      &        -v1cdij*sinphi1p2+v2cdij*sinphi1m2) 
4531           enddo
4532         enddo
4533         gloc(i-3,icg)=gloc(i-3,icg)+wtor_d*fact2*gloci1
4534         gloc(i-2,icg)=gloc(i-2,icg)+wtor_d*fact2*gloci2
4535  1215   continue
4536       enddo
4537       return
4538       end
4539 #endif
4540 c------------------------------------------------------------------------------
4541       subroutine eback_sc_corr(esccor)
4542 c 7/21/2007 Correlations between the backbone-local and side-chain-local
4543 c        conformational states; temporarily implemented as differences
4544 c        between UNRES torsional potentials (dependent on three types of
4545 c        residues) and the torsional potentials dependent on all 20 types
4546 c        of residues computed from AM1 energy surfaces of terminally-blocked
4547 c        amino-acid residues.
4548       implicit real*8 (a-h,o-z)
4549       include 'DIMENSIONS'
4550       include 'DIMENSIONS.ZSCOPT'
4551       include 'COMMON.VAR'
4552       include 'COMMON.GEO'
4553       include 'COMMON.LOCAL'
4554       include 'COMMON.TORSION'
4555       include 'COMMON.SCCOR'
4556       include 'COMMON.INTERACT'
4557       include 'COMMON.DERIV'
4558       include 'COMMON.CHAIN'
4559       include 'COMMON.NAMES'
4560       include 'COMMON.IOUNITS'
4561       include 'COMMON.FFIELD'
4562       include 'COMMON.CONTROL'
4563       logical lprn
4564 C Set lprn=.true. for debugging
4565       lprn=.false.
4566 c      lprn=.true.
4567 c      write (iout,*) "EBACK_SC_COR",itau_start,itau_end,nterm_sccor
4568       esccor=0.0D0
4569       do i=itau_start,itau_end
4570         esccor_ii=0.0D0
4571         isccori=isccortyp(itype(i-2))
4572         isccori1=isccortyp(itype(i-1))
4573         phii=phi(i)
4574 cccc  Added 9 May 2012
4575 cc Tauangle is torsional engle depending on the value of first digit 
4576 c(see comment below)
4577 cc Omicron is flat angle depending on the value of first digit 
4578 c(see comment below)
4579
4580
4581         do intertyp=1,3 !intertyp
4582 cc Added 09 May 2012 (Adasko)
4583 cc  Intertyp means interaction type of backbone mainchain correlation: 
4584 c   1 = SC...Ca...Ca...Ca
4585 c   2 = Ca...Ca...Ca...SC
4586 c   3 = SC...Ca...Ca...SCi
4587         gloci=0.0D0
4588         if (((intertyp.eq.3).and.((itype(i-2).eq.10).or.
4589      &      (itype(i-1).eq.10).or.(itype(i-2).eq.21).or.
4590      &      (itype(i-1).eq.21)))
4591      &    .or. ((intertyp.eq.1).and.((itype(i-2).eq.10)
4592      &     .or.(itype(i-2).eq.21)))
4593      &    .or.((intertyp.eq.2).and.((itype(i-1).eq.10).or.
4594      &      (itype(i-1).eq.21)))) cycle
4595         if ((intertyp.eq.2).and.(i.eq.4).and.(itype(1).eq.21)) cycle
4596         if ((intertyp.eq.1).and.(i.eq.nres).and.(itype(nres).eq.21))
4597      & cycle
4598         do j=1,nterm_sccor(isccori,isccori1)
4599           v1ij=v1sccor(j,intertyp,isccori,isccori1)
4600           v2ij=v2sccor(j,intertyp,isccori,isccori1)
4601           cosphi=dcos(j*tauangle(intertyp,i))
4602           sinphi=dsin(j*tauangle(intertyp,i))
4603           esccor=esccor+v1ij*cosphi+v2ij*sinphi
4604 #ifdef DEBUG
4605           esccor_ii=esccor_ii+v1ij*cosphi+v2ij*sinphi
4606 #endif
4607           gloci=gloci+j*(v2ij*cosphi-v1ij*sinphi)
4608         enddo
4609         gloc_sc(intertyp,i-3,icg)=gloc_sc(intertyp,i-3,icg)+wsccor*gloci
4610 c       write (iout,*) "WTF",intertyp,i,itype(i),v1ij*cosphi+v2ij*sinphi
4611 c     &gloc_sc(intertyp,i-3,icg)
4612         if (lprn)
4613      &  write (iout,'(2(a3,2x,i3,2x),2i3,6f8.3/26x,6f8.3/)')
4614      &  restyp(itype(i-2)),i-2,restyp(itype(i-1)),i-1,itori,itori1,
4615      &  (v1sccor(j,intertyp,itori,itori1),j=1,6)
4616      & ,(v2sccor(j,intertyp,itori,itori1),j=1,6)
4617         gsccor_loc(i-3)=gsccor_loc(i-3)+gloci
4618        enddo !intertyp
4619       enddo
4620 c        do i=1,nres
4621 c        write (iout,*) "W@T@F",  gloc_sc(1,i,icg),gloc(i,icg)
4622 c        enddo
4623       return
4624       end
4625 c------------------------------------------------------------------------------
4626       subroutine multibody(ecorr)
4627 C This subroutine calculates multi-body contributions to energy following
4628 C the idea of Skolnick et al. If side chains I and J make a contact and
4629 C at the same time side chains I+1 and J+1 make a contact, an extra 
4630 C contribution equal to sqrt(eps(i,j)*eps(i+1,j+1)) is added.
4631       implicit real*8 (a-h,o-z)
4632       include 'DIMENSIONS'
4633       include 'COMMON.IOUNITS'
4634       include 'COMMON.DERIV'
4635       include 'COMMON.INTERACT'
4636       include 'COMMON.CONTACTS'
4637       double precision gx(3),gx1(3)
4638       logical lprn
4639
4640 C Set lprn=.true. for debugging
4641       lprn=.false.
4642
4643       if (lprn) then
4644         write (iout,'(a)') 'Contact function values:'
4645         do i=nnt,nct-2
4646           write (iout,'(i2,20(1x,i2,f10.5))') 
4647      &        i,(jcont(j,i),facont(j,i),j=1,num_cont(i))
4648         enddo
4649       endif
4650       ecorr=0.0D0
4651       do i=nnt,nct
4652         do j=1,3
4653           gradcorr(j,i)=0.0D0
4654           gradxorr(j,i)=0.0D0
4655         enddo
4656       enddo
4657       do i=nnt,nct-2
4658
4659         DO ISHIFT = 3,4
4660
4661         i1=i+ishift
4662         num_conti=num_cont(i)
4663         num_conti1=num_cont(i1)
4664         do jj=1,num_conti
4665           j=jcont(jj,i)
4666           do kk=1,num_conti1
4667             j1=jcont(kk,i1)
4668             if (j1.eq.j+ishift .or. j1.eq.j-ishift) then
4669 cd          write(iout,*)'i=',i,' j=',j,' i1=',i1,' j1=',j1,
4670 cd   &                   ' ishift=',ishift
4671 C Contacts I--J and I+ISHIFT--J+-ISHIFT1 occur simultaneously. 
4672 C The system gains extra energy.
4673               ecorr=ecorr+esccorr(i,j,i1,j1,jj,kk)
4674             endif   ! j1==j+-ishift
4675           enddo     ! kk  
4676         enddo       ! jj
4677
4678         ENDDO ! ISHIFT
4679
4680       enddo         ! i
4681       return
4682       end
4683 c------------------------------------------------------------------------------
4684       double precision function esccorr(i,j,k,l,jj,kk)
4685       implicit real*8 (a-h,o-z)
4686       include 'DIMENSIONS'
4687       include 'COMMON.IOUNITS'
4688       include 'COMMON.DERIV'
4689       include 'COMMON.INTERACT'
4690       include 'COMMON.CONTACTS'
4691       double precision gx(3),gx1(3)
4692       logical lprn
4693       lprn=.false.
4694       eij=facont(jj,i)
4695       ekl=facont(kk,k)
4696 cd    write (iout,'(4i5,3f10.5)') i,j,k,l,eij,ekl,-eij*ekl
4697 C Calculate the multi-body contribution to energy.
4698 C Calculate multi-body contributions to the gradient.
4699 cd    write (iout,'(2(2i3,3f10.5))')i,j,(gacont(m,jj,i),m=1,3),
4700 cd   & k,l,(gacont(m,kk,k),m=1,3)
4701       do m=1,3
4702         gx(m) =ekl*gacont(m,jj,i)
4703         gx1(m)=eij*gacont(m,kk,k)
4704         gradxorr(m,i)=gradxorr(m,i)-gx(m)
4705         gradxorr(m,j)=gradxorr(m,j)+gx(m)
4706         gradxorr(m,k)=gradxorr(m,k)-gx1(m)
4707         gradxorr(m,l)=gradxorr(m,l)+gx1(m)
4708       enddo
4709       do m=i,j-1
4710         do ll=1,3
4711           gradcorr(ll,m)=gradcorr(ll,m)+gx(ll)
4712         enddo
4713       enddo
4714       do m=k,l-1
4715         do ll=1,3
4716           gradcorr(ll,m)=gradcorr(ll,m)+gx1(ll)
4717         enddo
4718       enddo 
4719       esccorr=-eij*ekl
4720       return
4721       end
4722 c------------------------------------------------------------------------------
4723 #ifdef MPL
4724       subroutine pack_buffer(dimen1,dimen2,atom,indx,buffer)
4725       implicit real*8 (a-h,o-z)
4726       include 'DIMENSIONS' 
4727       integer dimen1,dimen2,atom,indx
4728       double precision buffer(dimen1,dimen2)
4729       double precision zapas 
4730       common /contacts_hb/ zapas(3,20,maxres,7),
4731      &   facont_hb(20,maxres),ees0p(20,maxres),ees0m(20,maxres),
4732      &         num_cont_hb(maxres),jcont_hb(20,maxres)
4733       num_kont=num_cont_hb(atom)
4734       do i=1,num_kont
4735         do k=1,7
4736           do j=1,3
4737             buffer(i,indx+(k-1)*3+j)=zapas(j,i,atom,k)
4738           enddo ! j
4739         enddo ! k
4740         buffer(i,indx+22)=facont_hb(i,atom)
4741         buffer(i,indx+23)=ees0p(i,atom)
4742         buffer(i,indx+24)=ees0m(i,atom)
4743         buffer(i,indx+25)=dfloat(jcont_hb(i,atom))
4744       enddo ! i
4745       buffer(1,indx+26)=dfloat(num_kont)
4746       return
4747       end
4748 c------------------------------------------------------------------------------
4749       subroutine unpack_buffer(dimen1,dimen2,atom,indx,buffer)
4750       implicit real*8 (a-h,o-z)
4751       include 'DIMENSIONS' 
4752       integer dimen1,dimen2,atom,indx
4753       double precision buffer(dimen1,dimen2)
4754       double precision zapas 
4755       common /contacts_hb/ zapas(3,20,maxres,7),
4756      &         facont_hb(20,maxres),ees0p(20,maxres),ees0m(20,maxres),
4757      &         num_cont_hb(maxres),jcont_hb(20,maxres)
4758       num_kont=buffer(1,indx+26)
4759       num_kont_old=num_cont_hb(atom)
4760       num_cont_hb(atom)=num_kont+num_kont_old
4761       do i=1,num_kont
4762         ii=i+num_kont_old
4763         do k=1,7    
4764           do j=1,3
4765             zapas(j,ii,atom,k)=buffer(i,indx+(k-1)*3+j)
4766           enddo ! j 
4767         enddo ! k 
4768         facont_hb(ii,atom)=buffer(i,indx+22)
4769         ees0p(ii,atom)=buffer(i,indx+23)
4770         ees0m(ii,atom)=buffer(i,indx+24)
4771         jcont_hb(ii,atom)=buffer(i,indx+25)
4772       enddo ! i
4773       return
4774       end
4775 c------------------------------------------------------------------------------
4776 #endif
4777       subroutine multibody_hb(ecorr,ecorr5,ecorr6,n_corr,n_corr1)
4778 C This subroutine calculates multi-body contributions to hydrogen-bonding 
4779       implicit real*8 (a-h,o-z)
4780       include 'DIMENSIONS'
4781       include 'DIMENSIONS.ZSCOPT'
4782       include 'COMMON.IOUNITS'
4783 #ifdef MPL
4784       include 'COMMON.INFO'
4785 #endif
4786       include 'COMMON.FFIELD'
4787       include 'COMMON.DERIV'
4788       include 'COMMON.INTERACT'
4789       include 'COMMON.CONTACTS'
4790 #ifdef MPL
4791       parameter (max_cont=maxconts)
4792       parameter (max_dim=2*(8*3+2))
4793       parameter (msglen1=max_cont*max_dim*4)
4794       parameter (msglen2=2*msglen1)
4795       integer source,CorrelType,CorrelID,Error
4796       double precision buffer(max_cont,max_dim)
4797 #endif
4798       double precision gx(3),gx1(3)
4799       logical lprn,ldone
4800
4801 C Set lprn=.true. for debugging
4802       lprn=.false.
4803 #ifdef MPL
4804       n_corr=0
4805       n_corr1=0
4806       if (fgProcs.le.1) goto 30
4807       if (lprn) then
4808         write (iout,'(a)') 'Contact function values:'
4809         do i=nnt,nct-2
4810           write (iout,'(2i3,50(1x,i2,f5.2))') 
4811      &    i,num_cont_hb(i),(jcont_hb(j,i),facont_hb(j,i),
4812      &    j=1,num_cont_hb(i))
4813         enddo
4814       endif
4815 C Caution! Following code assumes that electrostatic interactions concerning
4816 C a given atom are split among at most two processors!
4817       CorrelType=477
4818       CorrelID=MyID+1
4819       ldone=.false.
4820       do i=1,max_cont
4821         do j=1,max_dim
4822           buffer(i,j)=0.0D0
4823         enddo
4824       enddo
4825       mm=mod(MyRank,2)
4826 cd    write (iout,*) 'MyRank',MyRank,' mm',mm
4827       if (mm) 20,20,10 
4828    10 continue
4829 cd    write (iout,*) 'Sending: MyRank',MyRank,' mm',mm,' ldone',ldone
4830       if (MyRank.gt.0) then
4831 C Send correlation contributions to the preceding processor
4832         msglen=msglen1
4833         nn=num_cont_hb(iatel_s)
4834         call pack_buffer(max_cont,max_dim,iatel_s,0,buffer)
4835 cd      write (iout,*) 'The BUFFER array:'
4836 cd      do i=1,nn
4837 cd        write (iout,'(i2,9(3f8.3,2x))') i,(buffer(i,j),j=1,26)
4838 cd      enddo
4839         if (ielstart(iatel_s).gt.iatel_s+ispp) then
4840           msglen=msglen2
4841             call pack_buffer(max_cont,max_dim,iatel_s+1,26,buffer)
4842 C Clear the contacts of the atom passed to the neighboring processor
4843         nn=num_cont_hb(iatel_s+1)
4844 cd      do i=1,nn
4845 cd        write (iout,'(i2,9(3f8.3,2x))') i,(buffer(i,j+26),j=1,26)
4846 cd      enddo
4847             num_cont_hb(iatel_s)=0
4848         endif 
4849 cd      write (iout,*) 'Processor ',MyID,MyRank,
4850 cd   & ' is sending correlation contribution to processor',MyID-1,
4851 cd   & ' msglen=',msglen
4852 cd      write (*,*) 'Processor ',MyID,MyRank,
4853 cd   & ' is sending correlation contribution to processor',MyID-1,
4854 cd   & ' msglen=',msglen,' CorrelType=',CorrelType
4855         call mp_bsend(buffer,msglen,MyID-1,CorrelType,CorrelID)
4856 cd      write (iout,*) 'Processor ',MyID,
4857 cd   & ' has sent correlation contribution to processor',MyID-1,
4858 cd   & ' msglen=',msglen,' CorrelID=',CorrelID
4859 cd      write (*,*) 'Processor ',MyID,
4860 cd   & ' has sent correlation contribution to processor',MyID-1,
4861 cd   & ' msglen=',msglen,' CorrelID=',CorrelID
4862         msglen=msglen1
4863       endif ! (MyRank.gt.0)
4864       if (ldone) goto 30
4865       ldone=.true.
4866    20 continue
4867 cd    write (iout,*) 'Receiving: MyRank',MyRank,' mm',mm,' ldone',ldone
4868       if (MyRank.lt.fgProcs-1) then
4869 C Receive correlation contributions from the next processor
4870         msglen=msglen1
4871         if (ielend(iatel_e).lt.nct-1) msglen=msglen2
4872 cd      write (iout,*) 'Processor',MyID,
4873 cd   & ' is receiving correlation contribution from processor',MyID+1,
4874 cd   & ' msglen=',msglen,' CorrelType=',CorrelType
4875 cd      write (*,*) 'Processor',MyID,
4876 cd   & ' is receiving correlation contribution from processor',MyID+1,
4877 cd   & ' msglen=',msglen,' CorrelType=',CorrelType
4878         nbytes=-1
4879         do while (nbytes.le.0)
4880           call mp_probe(MyID+1,CorrelType,nbytes)
4881         enddo
4882 cd      print *,'Processor',MyID,' msglen',msglen,' nbytes',nbytes
4883         call mp_brecv(buffer,msglen,MyID+1,CorrelType,nbytes)
4884 cd      write (iout,*) 'Processor',MyID,
4885 cd   & ' has received correlation contribution from processor',MyID+1,
4886 cd   & ' msglen=',msglen,' nbytes=',nbytes
4887 cd      write (iout,*) 'The received BUFFER array:'
4888 cd      do i=1,max_cont
4889 cd        write (iout,'(i2,9(3f8.3,2x))') i,(buffer(i,j),j=1,52)
4890 cd      enddo
4891         if (msglen.eq.msglen1) then
4892           call unpack_buffer(max_cont,max_dim,iatel_e+1,0,buffer)
4893         else if (msglen.eq.msglen2)  then
4894           call unpack_buffer(max_cont,max_dim,iatel_e,0,buffer) 
4895           call unpack_buffer(max_cont,max_dim,iatel_e+1,26,buffer) 
4896         else
4897           write (iout,*) 
4898      & 'ERROR!!!! message length changed while processing correlations.'
4899           write (*,*) 
4900      & 'ERROR!!!! message length changed while processing correlations.'
4901           call mp_stopall(Error)
4902         endif ! msglen.eq.msglen1
4903       endif ! MyRank.lt.fgProcs-1
4904       if (ldone) goto 30
4905       ldone=.true.
4906       goto 10
4907    30 continue
4908 #endif
4909       if (lprn) then
4910         write (iout,'(a)') 'Contact function values:'
4911         do i=nnt,nct-2
4912           write (iout,'(2i3,50(1x,i2,f5.2))') 
4913      &    i,num_cont_hb(i),(jcont_hb(j,i),facont_hb(j,i),
4914      &    j=1,num_cont_hb(i))
4915         enddo
4916       endif
4917       ecorr=0.0D0
4918 C Remove the loop below after debugging !!!
4919       do i=nnt,nct
4920         do j=1,3
4921           gradcorr(j,i)=0.0D0
4922           gradxorr(j,i)=0.0D0
4923         enddo
4924       enddo
4925 C Calculate the local-electrostatic correlation terms
4926       do i=iatel_s,iatel_e+1
4927         i1=i+1
4928         num_conti=num_cont_hb(i)
4929         num_conti1=num_cont_hb(i+1)
4930         do jj=1,num_conti
4931           j=jcont_hb(jj,i)
4932           do kk=1,num_conti1
4933             j1=jcont_hb(kk,i1)
4934 c            write (iout,*) 'i=',i,' j=',j,' i1=',i1,' j1=',j1,
4935 c     &         ' jj=',jj,' kk=',kk
4936             if (j1.eq.j+1 .or. j1.eq.j-1) then
4937 C Contacts I-J and (I+1)-(J+1) or (I+1)-(J-1) occur simultaneously. 
4938 C The system gains extra energy.
4939               ecorr=ecorr+ehbcorr(i,j,i+1,j1,jj,kk,0.72D0,0.32D0)
4940               n_corr=n_corr+1
4941             else if (j1.eq.j) then
4942 C Contacts I-J and I-(J+1) occur simultaneously. 
4943 C The system loses extra energy.
4944 c             ecorr=ecorr+ehbcorr(i,j,i+1,j,jj,kk,0.60D0,-0.40D0) 
4945             endif
4946           enddo ! kk
4947           do kk=1,num_conti
4948             j1=jcont_hb(kk,i)
4949 c           write (iout,*) 'i=',i,' j=',j,' i1=',i1,' j1=',j1,
4950 c    &         ' jj=',jj,' kk=',kk
4951             if (j1.eq.j+1) then
4952 C Contacts I-J and (I+1)-J occur simultaneously. 
4953 C The system loses extra energy.
4954 c             ecorr=ecorr+ehbcorr(i,j,i,j+1,jj,kk,0.60D0,-0.40D0)
4955             endif ! j1==j+1
4956           enddo ! kk
4957         enddo ! jj
4958       enddo ! i
4959       return
4960       end
4961 c------------------------------------------------------------------------------
4962       subroutine multibody_eello(ecorr,ecorr5,ecorr6,eturn6,n_corr,
4963      &  n_corr1)
4964 C This subroutine calculates multi-body contributions to hydrogen-bonding 
4965       implicit real*8 (a-h,o-z)
4966       include 'DIMENSIONS'
4967       include 'DIMENSIONS.ZSCOPT'
4968       include 'COMMON.IOUNITS'
4969 #ifdef MPL
4970       include 'COMMON.INFO'
4971 #endif
4972       include 'COMMON.FFIELD'
4973       include 'COMMON.DERIV'
4974       include 'COMMON.INTERACT'
4975       include 'COMMON.CONTACTS'
4976 #ifdef MPL
4977       parameter (max_cont=maxconts)
4978       parameter (max_dim=2*(8*3+2))
4979       parameter (msglen1=max_cont*max_dim*4)
4980       parameter (msglen2=2*msglen1)
4981       integer source,CorrelType,CorrelID,Error
4982       double precision buffer(max_cont,max_dim)
4983 #endif
4984       double precision gx(3),gx1(3)
4985       logical lprn,ldone
4986
4987 C Set lprn=.true. for debugging
4988       lprn=.false.
4989       eturn6=0.0d0
4990 #ifdef MPL
4991       n_corr=0
4992       n_corr1=0
4993       if (fgProcs.le.1) goto 30
4994       if (lprn) then
4995         write (iout,'(a)') 'Contact function values:'
4996         do i=nnt,nct-2
4997           write (iout,'(2i3,50(1x,i2,f5.2))') 
4998      &    i,num_cont_hb(i),(jcont_hb(j,i),facont_hb(j,i),
4999      &    j=1,num_cont_hb(i))
5000         enddo
5001       endif
5002 C Caution! Following code assumes that electrostatic interactions concerning
5003 C a given atom are split among at most two processors!
5004       CorrelType=477
5005       CorrelID=MyID+1
5006       ldone=.false.
5007       do i=1,max_cont
5008         do j=1,max_dim
5009           buffer(i,j)=0.0D0
5010         enddo
5011       enddo
5012       mm=mod(MyRank,2)
5013 cd    write (iout,*) 'MyRank',MyRank,' mm',mm
5014       if (mm) 20,20,10 
5015    10 continue
5016 cd    write (iout,*) 'Sending: MyRank',MyRank,' mm',mm,' ldone',ldone
5017       if (MyRank.gt.0) then
5018 C Send correlation contributions to the preceding processor
5019         msglen=msglen1
5020         nn=num_cont_hb(iatel_s)
5021         call pack_buffer(max_cont,max_dim,iatel_s,0,buffer)
5022 cd      write (iout,*) 'The BUFFER array:'
5023 cd      do i=1,nn
5024 cd        write (iout,'(i2,9(3f8.3,2x))') i,(buffer(i,j),j=1,26)
5025 cd      enddo
5026         if (ielstart(iatel_s).gt.iatel_s+ispp) then
5027           msglen=msglen2
5028             call pack_buffer(max_cont,max_dim,iatel_s+1,26,buffer)
5029 C Clear the contacts of the atom passed to the neighboring processor
5030         nn=num_cont_hb(iatel_s+1)
5031 cd      do i=1,nn
5032 cd        write (iout,'(i2,9(3f8.3,2x))') i,(buffer(i,j+26),j=1,26)
5033 cd      enddo
5034             num_cont_hb(iatel_s)=0
5035         endif 
5036 cd      write (iout,*) 'Processor ',MyID,MyRank,
5037 cd   & ' is sending correlation contribution to processor',MyID-1,
5038 cd   & ' msglen=',msglen
5039 cd      write (*,*) 'Processor ',MyID,MyRank,
5040 cd   & ' is sending correlation contribution to processor',MyID-1,
5041 cd   & ' msglen=',msglen,' CorrelType=',CorrelType
5042         call mp_bsend(buffer,msglen,MyID-1,CorrelType,CorrelID)
5043 cd      write (iout,*) 'Processor ',MyID,
5044 cd   & ' has sent correlation contribution to processor',MyID-1,
5045 cd   & ' msglen=',msglen,' CorrelID=',CorrelID
5046 cd      write (*,*) 'Processor ',MyID,
5047 cd   & ' has sent correlation contribution to processor',MyID-1,
5048 cd   & ' msglen=',msglen,' CorrelID=',CorrelID
5049         msglen=msglen1
5050       endif ! (MyRank.gt.0)
5051       if (ldone) goto 30
5052       ldone=.true.
5053    20 continue
5054 cd    write (iout,*) 'Receiving: MyRank',MyRank,' mm',mm,' ldone',ldone
5055       if (MyRank.lt.fgProcs-1) then
5056 C Receive correlation contributions from the next processor
5057         msglen=msglen1
5058         if (ielend(iatel_e).lt.nct-1) msglen=msglen2
5059 cd      write (iout,*) 'Processor',MyID,
5060 cd   & ' is receiving correlation contribution from processor',MyID+1,
5061 cd   & ' msglen=',msglen,' CorrelType=',CorrelType
5062 cd      write (*,*) 'Processor',MyID,
5063 cd   & ' is receiving correlation contribution from processor',MyID+1,
5064 cd   & ' msglen=',msglen,' CorrelType=',CorrelType
5065         nbytes=-1
5066         do while (nbytes.le.0)
5067           call mp_probe(MyID+1,CorrelType,nbytes)
5068         enddo
5069 cd      print *,'Processor',MyID,' msglen',msglen,' nbytes',nbytes
5070         call mp_brecv(buffer,msglen,MyID+1,CorrelType,nbytes)
5071 cd      write (iout,*) 'Processor',MyID,
5072 cd   & ' has received correlation contribution from processor',MyID+1,
5073 cd   & ' msglen=',msglen,' nbytes=',nbytes
5074 cd      write (iout,*) 'The received BUFFER array:'
5075 cd      do i=1,max_cont
5076 cd        write (iout,'(i2,9(3f8.3,2x))') i,(buffer(i,j),j=1,52)
5077 cd      enddo
5078         if (msglen.eq.msglen1) then
5079           call unpack_buffer(max_cont,max_dim,iatel_e+1,0,buffer)
5080         else if (msglen.eq.msglen2)  then
5081           call unpack_buffer(max_cont,max_dim,iatel_e,0,buffer) 
5082           call unpack_buffer(max_cont,max_dim,iatel_e+1,26,buffer) 
5083         else
5084           write (iout,*) 
5085      & 'ERROR!!!! message length changed while processing correlations.'
5086           write (*,*) 
5087      & 'ERROR!!!! message length changed while processing correlations.'
5088           call mp_stopall(Error)
5089         endif ! msglen.eq.msglen1
5090       endif ! MyRank.lt.fgProcs-1
5091       if (ldone) goto 30
5092       ldone=.true.
5093       goto 10
5094    30 continue
5095 #endif
5096       if (lprn) then
5097         write (iout,'(a)') 'Contact function values:'
5098         do i=nnt,nct-2
5099           write (iout,'(2i3,50(1x,i2,f5.2))') 
5100      &    i,num_cont_hb(i),(jcont_hb(j,i),facont_hb(j,i),
5101      &    j=1,num_cont_hb(i))
5102         enddo
5103       endif
5104       ecorr=0.0D0
5105       ecorr5=0.0d0
5106       ecorr6=0.0d0
5107 C Remove the loop below after debugging !!!
5108       do i=nnt,nct
5109         do j=1,3
5110           gradcorr(j,i)=0.0D0
5111           gradxorr(j,i)=0.0D0
5112         enddo
5113       enddo
5114 C Calculate the dipole-dipole interaction energies
5115       if (wcorr6.gt.0.0d0 .or. wturn6.gt.0.0d0) then
5116       do i=iatel_s,iatel_e+1
5117         num_conti=num_cont_hb(i)
5118         do jj=1,num_conti
5119           j=jcont_hb(jj,i)
5120           call dipole(i,j,jj)
5121         enddo
5122       enddo
5123       endif
5124 C Calculate the local-electrostatic correlation terms
5125       do i=iatel_s,iatel_e+1
5126         i1=i+1
5127         num_conti=num_cont_hb(i)
5128         num_conti1=num_cont_hb(i+1)
5129         do jj=1,num_conti
5130           j=jcont_hb(jj,i)
5131           do kk=1,num_conti1
5132             j1=jcont_hb(kk,i1)
5133 c            write (*,*) 'i=',i,' j=',j,' i1=',i1,' j1=',j1,
5134 c     &         ' jj=',jj,' kk=',kk
5135             if (j1.eq.j+1 .or. j1.eq.j-1) then
5136 C Contacts I-J and (I+1)-(J+1) or (I+1)-(J-1) occur simultaneously. 
5137 C The system gains extra energy.
5138               n_corr=n_corr+1
5139               sqd1=dsqrt(d_cont(jj,i))
5140               sqd2=dsqrt(d_cont(kk,i1))
5141               sred_geom = sqd1*sqd2
5142               IF (sred_geom.lt.cutoff_corr) THEN
5143                 call gcont(sred_geom,r0_corr,1.0D0,delt_corr,
5144      &            ekont,fprimcont)
5145 c               write (*,*) 'i=',i,' j=',j,' i1=',i1,' j1=',j1,
5146 c     &         ' jj=',jj,' kk=',kk
5147                 fac_prim1=0.5d0*sqd2/sqd1*fprimcont
5148                 fac_prim2=0.5d0*sqd1/sqd2*fprimcont
5149                 do l=1,3
5150                   g_contij(l,1)=fac_prim1*grij_hb_cont(l,jj,i)
5151                   g_contij(l,2)=fac_prim2*grij_hb_cont(l,kk,i1)
5152                 enddo
5153                 n_corr1=n_corr1+1
5154 cd               write (iout,*) 'sred_geom=',sred_geom,
5155 cd     &          ' ekont=',ekont,' fprim=',fprimcont
5156                 call calc_eello(i,j,i+1,j1,jj,kk)
5157                 if (wcorr4.gt.0.0d0) 
5158      &            ecorr=ecorr+eello4(i,j,i+1,j1,jj,kk)
5159                 if (wcorr5.gt.0.0d0)
5160      &            ecorr5=ecorr5+eello5(i,j,i+1,j1,jj,kk)
5161 c                print *,"wcorr5",ecorr5
5162 cd                write(2,*)'wcorr6',wcorr6,' wturn6',wturn6
5163 cd                write(2,*)'ijkl',i,j,i+1,j1 
5164                 if (wcorr6.gt.0.0d0 .and. (j.ne.i+4 .or. j1.ne.i+3
5165      &               .or. wturn6.eq.0.0d0))then
5166 cd                  write (iout,*) '******ecorr6: i,j,i+1,j1',i,j,i+1,j1
5167                   ecorr6=ecorr6+eello6(i,j,i+1,j1,jj,kk)
5168 cd                write (iout,*) 'ecorr',ecorr,' ecorr5=',ecorr5,
5169 cd     &            'ecorr6=',ecorr6
5170 cd                write (iout,'(4e15.5)') sred_geom,
5171 cd     &          dabs(eello4(i,j,i+1,j1,jj,kk)),
5172 cd     &          dabs(eello5(i,j,i+1,j1,jj,kk)),
5173 cd     &          dabs(eello6(i,j,i+1,j1,jj,kk))
5174                 else if (wturn6.gt.0.0d0
5175      &            .and. (j.eq.i+4 .and. j1.eq.i+3)) then
5176 cd                  write (iout,*) '******eturn6: i,j,i+1,j1',i,j,i+1,j1
5177                   eturn6=eturn6+eello_turn6(i,jj,kk)
5178 cd                  write (2,*) 'multibody_eello:eturn6',eturn6
5179                 endif
5180               ENDIF
5181 1111          continue
5182             else if (j1.eq.j) then
5183 C Contacts I-J and I-(J+1) occur simultaneously. 
5184 C The system loses extra energy.
5185 c             ecorr=ecorr+ehbcorr(i,j,i+1,j,jj,kk,0.60D0,-0.40D0) 
5186             endif
5187           enddo ! kk
5188           do kk=1,num_conti
5189             j1=jcont_hb(kk,i)
5190 c           write (iout,*) 'i=',i,' j=',j,' i1=',i1,' j1=',j1,
5191 c    &         ' jj=',jj,' kk=',kk
5192             if (j1.eq.j+1) then
5193 C Contacts I-J and (I+1)-J occur simultaneously. 
5194 C The system loses extra energy.
5195 c             ecorr=ecorr+ehbcorr(i,j,i,j+1,jj,kk,0.60D0,-0.40D0)
5196             endif ! j1==j+1
5197           enddo ! kk
5198         enddo ! jj
5199       enddo ! i
5200       return
5201       end
5202 c------------------------------------------------------------------------------
5203       double precision function ehbcorr(i,j,k,l,jj,kk,coeffp,coeffm)
5204       implicit real*8 (a-h,o-z)
5205       include 'DIMENSIONS'
5206       include 'COMMON.IOUNITS'
5207       include 'COMMON.DERIV'
5208       include 'COMMON.INTERACT'
5209       include 'COMMON.CONTACTS'
5210       double precision gx(3),gx1(3)
5211       logical lprn
5212       lprn=.false.
5213       eij=facont_hb(jj,i)
5214       ekl=facont_hb(kk,k)
5215       ees0pij=ees0p(jj,i)
5216       ees0pkl=ees0p(kk,k)
5217       ees0mij=ees0m(jj,i)
5218       ees0mkl=ees0m(kk,k)
5219       ekont=eij*ekl
5220       ees=-(coeffp*ees0pij*ees0pkl+coeffm*ees0mij*ees0mkl)
5221 cd    ees=-(coeffp*ees0pkl+coeffm*ees0mkl)
5222 C Following 4 lines for diagnostics.
5223 cd    ees0pkl=0.0D0
5224 cd    ees0pij=1.0D0
5225 cd    ees0mkl=0.0D0
5226 cd    ees0mij=1.0D0
5227 c     write (iout,*)'Contacts have occurred for peptide groups',i,j,
5228 c    &   ' and',k,l
5229 c     write (iout,*)'Contacts have occurred for peptide groups',
5230 c    &  i,j,' fcont:',eij,' eij',' eesij',ees0pij,ees0mij,' and ',k,l
5231 c    & ,' fcont ',ekl,' eeskl',ees0pkl,ees0mkl,' ees=',ees
5232 C Calculate the multi-body contribution to energy.
5233       ecorr=ecorr+ekont*ees
5234       if (calc_grad) then
5235 C Calculate multi-body contributions to the gradient.
5236       do ll=1,3
5237         ghalf=0.5D0*ees*ekl*gacont_hbr(ll,jj,i)
5238         gradcorr(ll,i)=gradcorr(ll,i)+ghalf
5239      &  -ekont*(coeffp*ees0pkl*gacontp_hb1(ll,jj,i)+
5240      &  coeffm*ees0mkl*gacontm_hb1(ll,jj,i))
5241         gradcorr(ll,j)=gradcorr(ll,j)+ghalf
5242      &  -ekont*(coeffp*ees0pkl*gacontp_hb2(ll,jj,i)+
5243      &  coeffm*ees0mkl*gacontm_hb2(ll,jj,i))
5244         ghalf=0.5D0*ees*eij*gacont_hbr(ll,kk,k)
5245         gradcorr(ll,k)=gradcorr(ll,k)+ghalf
5246      &  -ekont*(coeffp*ees0pij*gacontp_hb1(ll,kk,k)+
5247      &  coeffm*ees0mij*gacontm_hb1(ll,kk,k))
5248         gradcorr(ll,l)=gradcorr(ll,l)+ghalf
5249      &  -ekont*(coeffp*ees0pij*gacontp_hb2(ll,kk,k)+
5250      &  coeffm*ees0mij*gacontm_hb2(ll,kk,k))
5251       enddo
5252       do m=i+1,j-1
5253         do ll=1,3
5254           gradcorr(ll,m)=gradcorr(ll,m)+
5255      &     ees*ekl*gacont_hbr(ll,jj,i)-
5256      &     ekont*(coeffp*ees0pkl*gacontp_hb3(ll,jj,i)+
5257      &     coeffm*ees0mkl*gacontm_hb3(ll,jj,i))
5258         enddo
5259       enddo
5260       do m=k+1,l-1
5261         do ll=1,3
5262           gradcorr(ll,m)=gradcorr(ll,m)+
5263      &     ees*eij*gacont_hbr(ll,kk,k)-
5264      &     ekont*(coeffp*ees0pij*gacontp_hb3(ll,kk,k)+
5265      &     coeffm*ees0mij*gacontm_hb3(ll,kk,k))
5266         enddo
5267       enddo 
5268       endif
5269       ehbcorr=ekont*ees
5270       return
5271       end
5272 C---------------------------------------------------------------------------
5273       subroutine dipole(i,j,jj)
5274       implicit real*8 (a-h,o-z)
5275       include 'DIMENSIONS'
5276       include 'DIMENSIONS.ZSCOPT'
5277       include 'COMMON.IOUNITS'
5278       include 'COMMON.CHAIN'
5279       include 'COMMON.FFIELD'
5280       include 'COMMON.DERIV'
5281       include 'COMMON.INTERACT'
5282       include 'COMMON.CONTACTS'
5283       include 'COMMON.TORSION'
5284       include 'COMMON.VAR'
5285       include 'COMMON.GEO'
5286       dimension dipi(2,2),dipj(2,2),dipderi(2),dipderj(2),auxvec(2),
5287      &  auxmat(2,2)
5288       iti1 = itortyp(itype(i+1))
5289       if (j.lt.nres-1) then
5290         itj1 = itortyp(itype(j+1))
5291       else
5292         itj1=ntortyp+1
5293       endif
5294       do iii=1,2
5295         dipi(iii,1)=Ub2(iii,i)
5296         dipderi(iii)=Ub2der(iii,i)
5297         dipi(iii,2)=b1(iii,iti1)
5298         dipj(iii,1)=Ub2(iii,j)
5299         dipderj(iii)=Ub2der(iii,j)
5300         dipj(iii,2)=b1(iii,itj1)
5301       enddo
5302       kkk=0
5303       do iii=1,2
5304         call matvec2(a_chuj(1,1,jj,i),dipj(1,iii),auxvec(1)) 
5305         do jjj=1,2
5306           kkk=kkk+1
5307           dip(kkk,jj,i)=scalar2(dipi(1,jjj),auxvec(1))
5308         enddo
5309       enddo
5310       if (.not.calc_grad) return
5311       do kkk=1,5
5312         do lll=1,3
5313           mmm=0
5314           do iii=1,2
5315             call matvec2(a_chuj_der(1,1,lll,kkk,jj,i),dipj(1,iii),
5316      &        auxvec(1))
5317             do jjj=1,2
5318               mmm=mmm+1
5319               dipderx(lll,kkk,mmm,jj,i)=scalar2(dipi(1,jjj),auxvec(1))
5320             enddo
5321           enddo
5322         enddo
5323       enddo
5324       call transpose2(a_chuj(1,1,jj,i),auxmat(1,1))
5325       call matvec2(auxmat(1,1),dipderi(1),auxvec(1))
5326       do iii=1,2
5327         dipderg(iii,jj,i)=scalar2(auxvec(1),dipj(1,iii))
5328       enddo
5329       call matvec2(a_chuj(1,1,jj,i),dipderj(1),auxvec(1))
5330       do iii=1,2
5331         dipderg(iii+2,jj,i)=scalar2(auxvec(1),dipi(1,iii))
5332       enddo
5333       return
5334       end
5335 C---------------------------------------------------------------------------
5336       subroutine calc_eello(i,j,k,l,jj,kk)
5337
5338 C This subroutine computes matrices and vectors needed to calculate 
5339 C the fourth-, fifth-, and sixth-order local-electrostatic terms.
5340 C
5341       implicit real*8 (a-h,o-z)
5342       include 'DIMENSIONS'
5343       include 'DIMENSIONS.ZSCOPT'
5344       include 'COMMON.IOUNITS'
5345       include 'COMMON.CHAIN'
5346       include 'COMMON.DERIV'
5347       include 'COMMON.INTERACT'
5348       include 'COMMON.CONTACTS'
5349       include 'COMMON.TORSION'
5350       include 'COMMON.VAR'
5351       include 'COMMON.GEO'
5352       include 'COMMON.FFIELD'
5353       double precision aa1(2,2),aa2(2,2),aa1t(2,2),aa2t(2,2),
5354      &  aa1tder(2,2,3,5),aa2tder(2,2,3,5),auxmat(2,2)
5355       logical lprn
5356       common /kutas/ lprn
5357 cd      write (iout,*) 'calc_eello: i=',i,' j=',j,' k=',k,' l=',l,
5358 cd     & ' jj=',jj,' kk=',kk
5359 cd      if (i.ne.2 .or. j.ne.4 .or. k.ne.3 .or. l.ne.5) return
5360       do iii=1,2
5361         do jjj=1,2
5362           aa1(iii,jjj)=a_chuj(iii,jjj,jj,i)
5363           aa2(iii,jjj)=a_chuj(iii,jjj,kk,k)
5364         enddo
5365       enddo
5366       call transpose2(aa1(1,1),aa1t(1,1))
5367       call transpose2(aa2(1,1),aa2t(1,1))
5368       do kkk=1,5
5369         do lll=1,3
5370           call transpose2(a_chuj_der(1,1,lll,kkk,jj,i),
5371      &      aa1tder(1,1,lll,kkk))
5372           call transpose2(a_chuj_der(1,1,lll,kkk,kk,k),
5373      &      aa2tder(1,1,lll,kkk))
5374         enddo
5375       enddo 
5376       if (l.eq.j+1) then
5377 C parallel orientation of the two CA-CA-CA frames.
5378         if (i.gt.1) then
5379           iti=itortyp(itype(i))
5380         else
5381           iti=ntortyp+1
5382         endif
5383         itk1=itortyp(itype(k+1))
5384         itj=itortyp(itype(j))
5385         if (l.lt.nres-1) then
5386           itl1=itortyp(itype(l+1))
5387         else
5388           itl1=ntortyp+1
5389         endif
5390 C A1 kernel(j+1) A2T
5391 cd        do iii=1,2
5392 cd          write (iout,'(3f10.5,5x,3f10.5)') 
5393 cd     &     (EUg(iii,jjj,k),jjj=1,2),(EUg(iii,jjj,l),jjj=1,2)
5394 cd        enddo
5395         call kernel(aa1(1,1),aa2t(1,1),a_chuj_der(1,1,1,1,jj,i),
5396      &   aa2tder(1,1,1,1),1,.false.,EUg(1,1,l),EUgder(1,1,l),
5397      &   AEA(1,1,1),AEAderg(1,1,1),AEAderx(1,1,1,1,1,1))
5398 C Following matrices are needed only for 6-th order cumulants
5399         IF (wcorr6.gt.0.0d0) THEN
5400         call kernel(aa1(1,1),aa2t(1,1),a_chuj_der(1,1,1,1,jj,i),
5401      &   aa2tder(1,1,1,1),1,.false.,EUgC(1,1,l),EUgCder(1,1,l),
5402      &   AECA(1,1,1),AECAderg(1,1,1),AECAderx(1,1,1,1,1,1))
5403         call kernel(aa1(1,1),aa2t(1,1),a_chuj_der(1,1,1,1,jj,i),
5404      &   aa2tder(1,1,1,1),2,.false.,Ug2DtEUg(1,1,l),
5405      &   Ug2DtEUgder(1,1,1,l),ADtEA(1,1,1),ADtEAderg(1,1,1,1),
5406      &   ADtEAderx(1,1,1,1,1,1))
5407         lprn=.false.
5408         call kernel(aa1(1,1),aa2t(1,1),a_chuj_der(1,1,1,1,jj,i),
5409      &   aa2tder(1,1,1,1),2,.false.,DtUg2EUg(1,1,l),
5410      &   DtUg2EUgder(1,1,1,l),ADtEA1(1,1,1),ADtEA1derg(1,1,1,1),
5411      &   ADtEA1derx(1,1,1,1,1,1))
5412         ENDIF
5413 C End 6-th order cumulants
5414 cd        lprn=.false.
5415 cd        if (lprn) then
5416 cd        write (2,*) 'In calc_eello6'
5417 cd        do iii=1,2
5418 cd          write (2,*) 'iii=',iii
5419 cd          do kkk=1,5
5420 cd            write (2,*) 'kkk=',kkk
5421 cd            do jjj=1,2
5422 cd              write (2,'(3(2f10.5),5x)') 
5423 cd     &        ((ADtEA1derx(jjj,mmm,lll,kkk,iii,1),mmm=1,2),lll=1,3)
5424 cd            enddo
5425 cd          enddo
5426 cd        enddo
5427 cd        endif
5428         call transpose2(EUgder(1,1,k),auxmat(1,1))
5429         call matmat2(auxmat(1,1),AEA(1,1,1),EAEAderg(1,1,1,1))
5430         call transpose2(EUg(1,1,k),auxmat(1,1))
5431         call matmat2(auxmat(1,1),AEA(1,1,1),EAEA(1,1,1))
5432         call matmat2(auxmat(1,1),AEAderg(1,1,1),EAEAderg(1,1,2,1))
5433         do iii=1,2
5434           do kkk=1,5
5435             do lll=1,3
5436               call matmat2(auxmat(1,1),AEAderx(1,1,lll,kkk,iii,1),
5437      &          EAEAderx(1,1,lll,kkk,iii,1))
5438             enddo
5439           enddo
5440         enddo
5441 C A1T kernel(i+1) A2
5442         call kernel(aa1t(1,1),aa2(1,1),aa1tder(1,1,1,1),
5443      &   a_chuj_der(1,1,1,1,kk,k),1,.false.,EUg(1,1,k),EUgder(1,1,k),
5444      &   AEA(1,1,2),AEAderg(1,1,2),AEAderx(1,1,1,1,1,2))
5445 C Following matrices are needed only for 6-th order cumulants
5446         IF (wcorr6.gt.0.0d0) THEN
5447         call kernel(aa1t(1,1),aa2(1,1),aa1tder(1,1,1,1),
5448      &   a_chuj_der(1,1,1,1,kk,k),1,.false.,EUgC(1,1,k),EUgCder(1,1,k),
5449      &   AECA(1,1,2),AECAderg(1,1,2),AECAderx(1,1,1,1,1,2))
5450         call kernel(aa1t(1,1),aa2(1,1),aa1tder(1,1,1,1),
5451      &   a_chuj_der(1,1,1,1,kk,k),2,.false.,Ug2DtEUg(1,1,k),
5452      &   Ug2DtEUgder(1,1,1,k),ADtEA(1,1,2),ADtEAderg(1,1,1,2),
5453      &   ADtEAderx(1,1,1,1,1,2))
5454         call kernel(aa1t(1,1),aa2(1,1),aa1tder(1,1,1,1),
5455      &   a_chuj_der(1,1,1,1,kk,k),2,.false.,DtUg2EUg(1,1,k),
5456      &   DtUg2EUgder(1,1,1,k),ADtEA1(1,1,2),ADtEA1derg(1,1,1,2),
5457      &   ADtEA1derx(1,1,1,1,1,2))
5458         ENDIF
5459 C End 6-th order cumulants
5460         call transpose2(EUgder(1,1,l),auxmat(1,1))
5461         call matmat2(auxmat(1,1),AEA(1,1,2),EAEAderg(1,1,1,2))
5462         call transpose2(EUg(1,1,l),auxmat(1,1))
5463         call matmat2(auxmat(1,1),AEA(1,1,2),EAEA(1,1,2))
5464         call matmat2(auxmat(1,1),AEAderg(1,1,2),EAEAderg(1,1,2,2))
5465         do iii=1,2
5466           do kkk=1,5
5467             do lll=1,3
5468               call matmat2(auxmat(1,1),AEAderx(1,1,lll,kkk,iii,2),
5469      &          EAEAderx(1,1,lll,kkk,iii,2))
5470             enddo
5471           enddo
5472         enddo
5473 C AEAb1 and AEAb2
5474 C Calculate the vectors and their derivatives in virtual-bond dihedral angles.
5475 C They are needed only when the fifth- or the sixth-order cumulants are
5476 C indluded.
5477         IF (wcorr5.gt.0.0d0 .or. wcorr6.gt.0.0d0) THEN
5478         call transpose2(AEA(1,1,1),auxmat(1,1))
5479         call matvec2(auxmat(1,1),b1(1,iti),AEAb1(1,1,1))
5480         call matvec2(auxmat(1,1),Ub2(1,i),AEAb2(1,1,1))
5481         call matvec2(auxmat(1,1),Ub2der(1,i),AEAb2derg(1,2,1,1))
5482         call transpose2(AEAderg(1,1,1),auxmat(1,1))
5483         call matvec2(auxmat(1,1),b1(1,iti),AEAb1derg(1,1,1))
5484         call matvec2(auxmat(1,1),Ub2(1,i),AEAb2derg(1,1,1,1))
5485         call matvec2(AEA(1,1,1),b1(1,itk1),AEAb1(1,2,1))
5486         call matvec2(AEAderg(1,1,1),b1(1,itk1),AEAb1derg(1,2,1))
5487         call matvec2(AEA(1,1,1),Ub2(1,k+1),AEAb2(1,2,1))
5488         call matvec2(AEAderg(1,1,1),Ub2(1,k+1),AEAb2derg(1,1,2,1))
5489         call matvec2(AEA(1,1,1),Ub2der(1,k+1),AEAb2derg(1,2,2,1))
5490         call transpose2(AEA(1,1,2),auxmat(1,1))
5491         call matvec2(auxmat(1,1),b1(1,itj),AEAb1(1,1,2))
5492         call matvec2(auxmat(1,1),Ub2(1,j),AEAb2(1,1,2))
5493         call matvec2(auxmat(1,1),Ub2der(1,j),AEAb2derg(1,2,1,2))
5494         call transpose2(AEAderg(1,1,2),auxmat(1,1))
5495         call matvec2(auxmat(1,1),b1(1,itj),AEAb1derg(1,1,2))
5496         call matvec2(auxmat(1,1),Ub2(1,j),AEAb2derg(1,1,1,2))
5497         call matvec2(AEA(1,1,2),b1(1,itl1),AEAb1(1,2,2))
5498         call matvec2(AEAderg(1,1,2),b1(1,itl1),AEAb1derg(1,2,2))
5499         call matvec2(AEA(1,1,2),Ub2(1,l+1),AEAb2(1,2,2))
5500         call matvec2(AEAderg(1,1,2),Ub2(1,l+1),AEAb2derg(1,1,2,2))
5501         call matvec2(AEA(1,1,2),Ub2der(1,l+1),AEAb2derg(1,2,2,2))
5502 C Calculate the Cartesian derivatives of the vectors.
5503         do iii=1,2
5504           do kkk=1,5
5505             do lll=1,3
5506               call transpose2(AEAderx(1,1,lll,kkk,iii,1),auxmat(1,1))
5507               call matvec2(auxmat(1,1),b1(1,iti),
5508      &          AEAb1derx(1,lll,kkk,iii,1,1))
5509               call matvec2(auxmat(1,1),Ub2(1,i),
5510      &          AEAb2derx(1,lll,kkk,iii,1,1))
5511               call matvec2(AEAderx(1,1,lll,kkk,iii,1),b1(1,itk1),
5512      &          AEAb1derx(1,lll,kkk,iii,2,1))
5513               call matvec2(AEAderx(1,1,lll,kkk,iii,1),Ub2(1,k+1),
5514      &          AEAb2derx(1,lll,kkk,iii,2,1))
5515               call transpose2(AEAderx(1,1,lll,kkk,iii,2),auxmat(1,1))
5516               call matvec2(auxmat(1,1),b1(1,itj),
5517      &          AEAb1derx(1,lll,kkk,iii,1,2))
5518               call matvec2(auxmat(1,1),Ub2(1,j),
5519      &          AEAb2derx(1,lll,kkk,iii,1,2))
5520               call matvec2(AEAderx(1,1,lll,kkk,iii,2),b1(1,itl1),
5521      &          AEAb1derx(1,lll,kkk,iii,2,2))
5522               call matvec2(AEAderx(1,1,lll,kkk,iii,2),Ub2(1,l+1),
5523      &          AEAb2derx(1,lll,kkk,iii,2,2))
5524             enddo
5525           enddo
5526         enddo
5527         ENDIF
5528 C End vectors
5529       else
5530 C Antiparallel orientation of the two CA-CA-CA frames.
5531         if (i.gt.1) then
5532           iti=itortyp(itype(i))
5533         else
5534           iti=ntortyp+1
5535         endif
5536         itk1=itortyp(itype(k+1))
5537         itl=itortyp(itype(l))
5538         itj=itortyp(itype(j))
5539         if (j.lt.nres-1) then
5540           itj1=itortyp(itype(j+1))
5541         else 
5542           itj1=ntortyp+1
5543         endif
5544 C A2 kernel(j-1)T A1T
5545         call kernel(aa1(1,1),aa2t(1,1),a_chuj_der(1,1,1,1,jj,i),
5546      &   aa2tder(1,1,1,1),1,.true.,EUg(1,1,j),EUgder(1,1,j),
5547      &   AEA(1,1,1),AEAderg(1,1,1),AEAderx(1,1,1,1,1,1))
5548 C Following matrices are needed only for 6-th order cumulants
5549         IF (wcorr6.gt.0.0d0 .or. (wturn6.gt.0.0d0 .and.
5550      &     j.eq.i+4 .and. l.eq.i+3)) THEN
5551         call kernel(aa1(1,1),aa2t(1,1),a_chuj_der(1,1,1,1,jj,i),
5552      &   aa2tder(1,1,1,1),1,.true.,EUgC(1,1,j),EUgCder(1,1,j),
5553      &   AECA(1,1,1),AECAderg(1,1,1),AECAderx(1,1,1,1,1,1))
5554         call kernel(aa2(1,1),aa2t(1,1),a_chuj_der(1,1,1,1,jj,i),
5555      &   aa2tder(1,1,1,1),2,.true.,Ug2DtEUg(1,1,j),
5556      &   Ug2DtEUgder(1,1,1,j),ADtEA(1,1,1),ADtEAderg(1,1,1,1),
5557      &   ADtEAderx(1,1,1,1,1,1))
5558         call kernel(aa1(1,1),aa2t(1,1),a_chuj_der(1,1,1,1,jj,i),
5559      &   aa2tder(1,1,1,1),2,.true.,DtUg2EUg(1,1,j),
5560      &   DtUg2EUgder(1,1,1,j),ADtEA1(1,1,1),ADtEA1derg(1,1,1,1),
5561      &   ADtEA1derx(1,1,1,1,1,1))
5562         ENDIF
5563 C End 6-th order cumulants
5564         call transpose2(EUgder(1,1,k),auxmat(1,1))
5565         call matmat2(auxmat(1,1),AEA(1,1,1),EAEAderg(1,1,1,1))
5566         call transpose2(EUg(1,1,k),auxmat(1,1))
5567         call matmat2(auxmat(1,1),AEA(1,1,1),EAEA(1,1,1))
5568         call matmat2(auxmat(1,1),AEAderg(1,1,1),EAEAderg(1,1,2,1))
5569         do iii=1,2
5570           do kkk=1,5
5571             do lll=1,3
5572               call matmat2(auxmat(1,1),AEAderx(1,1,lll,kkk,iii,1),
5573      &          EAEAderx(1,1,lll,kkk,iii,1))
5574             enddo
5575           enddo
5576         enddo
5577 C A2T kernel(i+1)T A1
5578         call kernel(aa2t(1,1),aa1(1,1),aa2tder(1,1,1,1),
5579      &   a_chuj_der(1,1,1,1,jj,i),1,.true.,EUg(1,1,k),EUgder(1,1,k),
5580      &   AEA(1,1,2),AEAderg(1,1,2),AEAderx(1,1,1,1,1,2))
5581 C Following matrices are needed only for 6-th order cumulants
5582         IF (wcorr6.gt.0.0d0 .or. (wturn6.gt.0.0d0 .and.
5583      &     j.eq.i+4 .and. l.eq.i+3)) THEN
5584         call kernel(aa2t(1,1),aa1(1,1),aa2tder(1,1,1,1),
5585      &   a_chuj_der(1,1,1,1,jj,i),1,.true.,EUgC(1,1,k),EUgCder(1,1,k),
5586      &   AECA(1,1,2),AECAderg(1,1,2),AECAderx(1,1,1,1,1,2))
5587         call kernel(aa2t(1,1),aa1(1,1),aa2tder(1,1,1,1),
5588      &   a_chuj_der(1,1,1,1,jj,i),2,.true.,Ug2DtEUg(1,1,k),
5589      &   Ug2DtEUgder(1,1,1,k),ADtEA(1,1,2),ADtEAderg(1,1,1,2),
5590      &   ADtEAderx(1,1,1,1,1,2))
5591         call kernel(aa2t(1,1),aa1(1,1),aa2tder(1,1,1,1),
5592      &   a_chuj_der(1,1,1,1,jj,i),2,.true.,DtUg2EUg(1,1,k),
5593      &   DtUg2EUgder(1,1,1,k),ADtEA1(1,1,2),ADtEA1derg(1,1,1,2),
5594      &   ADtEA1derx(1,1,1,1,1,2))
5595         ENDIF
5596 C End 6-th order cumulants
5597         call transpose2(EUgder(1,1,j),auxmat(1,1))
5598         call matmat2(auxmat(1,1),AEA(1,1,1),EAEAderg(1,1,2,2))
5599         call transpose2(EUg(1,1,j),auxmat(1,1))
5600         call matmat2(auxmat(1,1),AEA(1,1,2),EAEA(1,1,2))
5601         call matmat2(auxmat(1,1),AEAderg(1,1,2),EAEAderg(1,1,2,2))
5602         do iii=1,2
5603           do kkk=1,5
5604             do lll=1,3
5605               call matmat2(auxmat(1,1),AEAderx(1,1,lll,kkk,iii,2),
5606      &          EAEAderx(1,1,lll,kkk,iii,2))
5607             enddo
5608           enddo
5609         enddo
5610 C AEAb1 and AEAb2
5611 C Calculate the vectors and their derivatives in virtual-bond dihedral angles.
5612 C They are needed only when the fifth- or the sixth-order cumulants are
5613 C indluded.
5614         IF (wcorr5.gt.0.0d0 .or. wcorr6.gt.0.0d0 .or.
5615      &    (wturn6.gt.0.0d0 .and. j.eq.i+4 .and. l.eq.i+3)) THEN
5616         call transpose2(AEA(1,1,1),auxmat(1,1))
5617         call matvec2(auxmat(1,1),b1(1,iti),AEAb1(1,1,1))
5618         call matvec2(auxmat(1,1),Ub2(1,i),AEAb2(1,1,1))
5619         call matvec2(auxmat(1,1),Ub2der(1,i),AEAb2derg(1,2,1,1))
5620         call transpose2(AEAderg(1,1,1),auxmat(1,1))
5621         call matvec2(auxmat(1,1),b1(1,iti),AEAb1derg(1,1,1))
5622         call matvec2(auxmat(1,1),Ub2(1,i),AEAb2derg(1,1,1,1))
5623         call matvec2(AEA(1,1,1),b1(1,itk1),AEAb1(1,2,1))
5624         call matvec2(AEAderg(1,1,1),b1(1,itk1),AEAb1derg(1,2,1))
5625         call matvec2(AEA(1,1,1),Ub2(1,k+1),AEAb2(1,2,1))
5626         call matvec2(AEAderg(1,1,1),Ub2(1,k+1),AEAb2derg(1,1,2,1))
5627         call matvec2(AEA(1,1,1),Ub2der(1,k+1),AEAb2derg(1,2,2,1))
5628         call transpose2(AEA(1,1,2),auxmat(1,1))
5629         call matvec2(auxmat(1,1),b1(1,itj1),AEAb1(1,1,2))
5630         call matvec2(auxmat(1,1),Ub2(1,l),AEAb2(1,1,2))
5631         call matvec2(auxmat(1,1),Ub2der(1,l),AEAb2derg(1,2,1,2))
5632         call transpose2(AEAderg(1,1,2),auxmat(1,1))
5633         call matvec2(auxmat(1,1),b1(1,itl),AEAb1(1,1,2))
5634         call matvec2(auxmat(1,1),Ub2(1,l),AEAb2derg(1,1,1,2))
5635         call matvec2(AEA(1,1,2),b1(1,itj1),AEAb1(1,2,2))
5636         call matvec2(AEAderg(1,1,2),b1(1,itj1),AEAb1derg(1,2,2))
5637         call matvec2(AEA(1,1,2),Ub2(1,j),AEAb2(1,2,2))
5638         call matvec2(AEAderg(1,1,2),Ub2(1,j),AEAb2derg(1,1,2,2))
5639         call matvec2(AEA(1,1,2),Ub2der(1,j),AEAb2derg(1,2,2,2))
5640 C Calculate the Cartesian derivatives of the vectors.
5641         do iii=1,2
5642           do kkk=1,5
5643             do lll=1,3
5644               call transpose2(AEAderx(1,1,lll,kkk,iii,1),auxmat(1,1))
5645               call matvec2(auxmat(1,1),b1(1,iti),
5646      &          AEAb1derx(1,lll,kkk,iii,1,1))
5647               call matvec2(auxmat(1,1),Ub2(1,i),
5648      &          AEAb2derx(1,lll,kkk,iii,1,1))
5649               call matvec2(AEAderx(1,1,lll,kkk,iii,1),b1(1,itk1),
5650      &          AEAb1derx(1,lll,kkk,iii,2,1))
5651               call matvec2(AEAderx(1,1,lll,kkk,iii,1),Ub2(1,k+1),
5652      &          AEAb2derx(1,lll,kkk,iii,2,1))
5653               call transpose2(AEAderx(1,1,lll,kkk,iii,2),auxmat(1,1))
5654               call matvec2(auxmat(1,1),b1(1,itl),
5655      &          AEAb1derx(1,lll,kkk,iii,1,2))
5656               call matvec2(auxmat(1,1),Ub2(1,l),
5657      &          AEAb2derx(1,lll,kkk,iii,1,2))
5658               call matvec2(AEAderx(1,1,lll,kkk,iii,2),b1(1,itj1),
5659      &          AEAb1derx(1,lll,kkk,iii,2,2))
5660               call matvec2(AEAderx(1,1,lll,kkk,iii,2),Ub2(1,j),
5661      &          AEAb2derx(1,lll,kkk,iii,2,2))
5662             enddo
5663           enddo
5664         enddo
5665         ENDIF
5666 C End vectors
5667       endif
5668       return
5669       end
5670 C---------------------------------------------------------------------------
5671       subroutine kernel(aa1,aa2t,aa1derx,aa2tderx,nderg,transp,
5672      &  KK,KKderg,AKA,AKAderg,AKAderx)
5673       implicit none
5674       integer nderg
5675       logical transp
5676       double precision aa1(2,2),aa2t(2,2),aa1derx(2,2,3,5),
5677      &  aa2tderx(2,2,3,5),KK(2,2),KKderg(2,2,nderg),AKA(2,2),
5678      &  AKAderg(2,2,nderg),AKAderx(2,2,3,5,2)
5679       integer iii,kkk,lll
5680       integer jjj,mmm
5681       logical lprn
5682       common /kutas/ lprn
5683       call prodmat3(aa1(1,1),aa2t(1,1),KK(1,1),transp,AKA(1,1))
5684       do iii=1,nderg 
5685         call prodmat3(aa1(1,1),aa2t(1,1),KKderg(1,1,iii),transp,
5686      &    AKAderg(1,1,iii))
5687       enddo
5688 cd      if (lprn) write (2,*) 'In kernel'
5689       do kkk=1,5
5690 cd        if (lprn) write (2,*) 'kkk=',kkk
5691         do lll=1,3
5692           call prodmat3(aa1derx(1,1,lll,kkk),aa2t(1,1),
5693      &      KK(1,1),transp,AKAderx(1,1,lll,kkk,1))
5694 cd          if (lprn) then
5695 cd            write (2,*) 'lll=',lll
5696 cd            write (2,*) 'iii=1'
5697 cd            do jjj=1,2
5698 cd              write (2,'(3(2f10.5),5x)') 
5699 cd     &        (AKAderx(jjj,mmm,lll,kkk,1),mmm=1,2)
5700 cd            enddo
5701 cd          endif
5702           call prodmat3(aa1(1,1),aa2tderx(1,1,lll,kkk),
5703      &      KK(1,1),transp,AKAderx(1,1,lll,kkk,2))
5704 cd          if (lprn) then
5705 cd            write (2,*) 'lll=',lll
5706 cd            write (2,*) 'iii=2'
5707 cd            do jjj=1,2
5708 cd              write (2,'(3(2f10.5),5x)') 
5709 cd     &        (AKAderx(jjj,mmm,lll,kkk,2),mmm=1,2)
5710 cd            enddo
5711 cd          endif
5712         enddo
5713       enddo
5714       return
5715       end
5716 C---------------------------------------------------------------------------
5717       double precision function eello4(i,j,k,l,jj,kk)
5718       implicit real*8 (a-h,o-z)
5719       include 'DIMENSIONS'
5720       include 'DIMENSIONS.ZSCOPT'
5721       include 'COMMON.IOUNITS'
5722       include 'COMMON.CHAIN'
5723       include 'COMMON.DERIV'
5724       include 'COMMON.INTERACT'
5725       include 'COMMON.CONTACTS'
5726       include 'COMMON.TORSION'
5727       include 'COMMON.VAR'
5728       include 'COMMON.GEO'
5729       double precision pizda(2,2),ggg1(3),ggg2(3)
5730 cd      if (i.ne.1 .or. j.ne.5 .or. k.ne.2 .or.l.ne.4) then
5731 cd        eello4=0.0d0
5732 cd        return
5733 cd      endif
5734 cd      print *,'eello4:',i,j,k,l,jj,kk
5735 cd      write (2,*) 'i',i,' j',j,' k',k,' l',l
5736 cd      call checkint4(i,j,k,l,jj,kk,eel4_num)
5737 cold      eij=facont_hb(jj,i)
5738 cold      ekl=facont_hb(kk,k)
5739 cold      ekont=eij*ekl
5740       eel4=-EAEA(1,1,1)-EAEA(2,2,1)
5741       if (calc_grad) then
5742 cd      eel41=-EAEA(1,1,2)-EAEA(2,2,2)
5743       gcorr_loc(k-1)=gcorr_loc(k-1)
5744      &   -ekont*(EAEAderg(1,1,1,1)+EAEAderg(2,2,1,1))
5745       if (l.eq.j+1) then
5746         gcorr_loc(l-1)=gcorr_loc(l-1)
5747      &     -ekont*(EAEAderg(1,1,2,1)+EAEAderg(2,2,2,1))
5748       else
5749         gcorr_loc(j-1)=gcorr_loc(j-1)
5750      &     -ekont*(EAEAderg(1,1,2,1)+EAEAderg(2,2,2,1))
5751       endif
5752       do iii=1,2
5753         do kkk=1,5
5754           do lll=1,3
5755             derx(lll,kkk,iii)=-EAEAderx(1,1,lll,kkk,iii,1)
5756      &                        -EAEAderx(2,2,lll,kkk,iii,1)
5757 cd            derx(lll,kkk,iii)=0.0d0
5758           enddo
5759         enddo
5760       enddo
5761 cd      gcorr_loc(l-1)=0.0d0
5762 cd      gcorr_loc(j-1)=0.0d0
5763 cd      gcorr_loc(k-1)=0.0d0
5764 cd      eel4=1.0d0
5765 cd      write (iout,*)'Contacts have occurred for peptide groups',
5766 cd     &  i,j,' fcont:',eij,' eij',' and ',k,l,
5767 cd     &  ' fcont ',ekl,' eel4=',eel4,' eel4_num',16*eel4_num
5768       if (j.lt.nres-1) then
5769         j1=j+1
5770         j2=j-1
5771       else
5772         j1=j-1
5773         j2=j-2
5774       endif
5775       if (l.lt.nres-1) then
5776         l1=l+1
5777         l2=l-1
5778       else
5779         l1=l-1
5780         l2=l-2
5781       endif
5782       do ll=1,3
5783 cold        ghalf=0.5d0*eel4*ekl*gacont_hbr(ll,jj,i)
5784         ggg1(ll)=eel4*g_contij(ll,1)
5785         ggg2(ll)=eel4*g_contij(ll,2)
5786         ghalf=0.5d0*ggg1(ll)
5787 cd        ghalf=0.0d0
5788         gradcorr(ll,i)=gradcorr(ll,i)+ghalf+ekont*derx(ll,2,1)
5789         gradcorr(ll,i+1)=gradcorr(ll,i+1)+ekont*derx(ll,3,1)
5790         gradcorr(ll,j)=gradcorr(ll,j)+ghalf+ekont*derx(ll,4,1)
5791         gradcorr(ll,j1)=gradcorr(ll,j1)+ekont*derx(ll,5,1)
5792 cold        ghalf=0.5d0*eel4*eij*gacont_hbr(ll,kk,k)
5793         ghalf=0.5d0*ggg2(ll)
5794 cd        ghalf=0.0d0
5795         gradcorr(ll,k)=gradcorr(ll,k)+ghalf+ekont*derx(ll,2,2)
5796         gradcorr(ll,k+1)=gradcorr(ll,k+1)+ekont*derx(ll,3,2)
5797         gradcorr(ll,l)=gradcorr(ll,l)+ghalf+ekont*derx(ll,4,2)
5798         gradcorr(ll,l1)=gradcorr(ll,l1)+ekont*derx(ll,5,2)
5799       enddo
5800 cd      goto 1112
5801       do m=i+1,j-1
5802         do ll=1,3
5803 cold          gradcorr(ll,m)=gradcorr(ll,m)+eel4*ekl*gacont_hbr(ll,jj,i)
5804           gradcorr(ll,m)=gradcorr(ll,m)+ggg1(ll)
5805         enddo
5806       enddo
5807       do m=k+1,l-1
5808         do ll=1,3
5809 cold          gradcorr(ll,m)=gradcorr(ll,m)+eel4*eij*gacont_hbr(ll,kk,k)
5810           gradcorr(ll,m)=gradcorr(ll,m)+ggg2(ll)
5811         enddo
5812       enddo
5813 1112  continue
5814       do m=i+2,j2
5815         do ll=1,3
5816           gradcorr(ll,m)=gradcorr(ll,m)+ekont*derx(ll,1,1)
5817         enddo
5818       enddo
5819       do m=k+2,l2
5820         do ll=1,3
5821           gradcorr(ll,m)=gradcorr(ll,m)+ekont*derx(ll,1,2)
5822         enddo
5823       enddo 
5824 cd      do iii=1,nres-3
5825 cd        write (2,*) iii,gcorr_loc(iii)
5826 cd      enddo
5827       endif
5828       eello4=ekont*eel4
5829 cd      write (2,*) 'ekont',ekont
5830 cd      write (iout,*) 'eello4',ekont*eel4
5831       return
5832       end
5833 C---------------------------------------------------------------------------
5834       double precision function eello5(i,j,k,l,jj,kk)
5835       implicit real*8 (a-h,o-z)
5836       include 'DIMENSIONS'
5837       include 'DIMENSIONS.ZSCOPT'
5838       include 'COMMON.IOUNITS'
5839       include 'COMMON.CHAIN'
5840       include 'COMMON.DERIV'
5841       include 'COMMON.INTERACT'
5842       include 'COMMON.CONTACTS'
5843       include 'COMMON.TORSION'
5844       include 'COMMON.VAR'
5845       include 'COMMON.GEO'
5846       double precision pizda(2,2),auxmat(2,2),auxmat1(2,2),vv(2)
5847       double precision ggg1(3),ggg2(3)
5848 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
5849 C                                                                              C
5850 C                            Parallel chains                                   C
5851 C                                                                              C
5852 C          o             o                   o             o                   C
5853 C         /l\           / \             \   / \           / \   /              C
5854 C        /   \         /   \             \ /   \         /   \ /               C
5855 C       j| o |l1       | o |              o| o |         | o |o                C
5856 C     \  |/k\|         |/ \|  /            |/ \|         |/ \|                 C
5857 C      \i/   \         /   \ /             /   \         /   \                 C
5858 C       o    k1             o                                                  C
5859 C         (I)          (II)                (III)          (IV)                 C
5860 C                                                                              C
5861 C      eello5_1        eello5_2            eello5_3       eello5_4             C
5862 C                                                                              C
5863 C                            Antiparallel chains                               C
5864 C                                                                              C
5865 C          o             o                   o             o                   C
5866 C         /j\           / \             \   / \           / \   /              C
5867 C        /   \         /   \             \ /   \         /   \ /               C
5868 C      j1| o |l        | o |              o| o |         | o |o                C
5869 C     \  |/k\|         |/ \|  /            |/ \|         |/ \|                 C
5870 C      \i/   \         /   \ /             /   \         /   \                 C
5871 C       o     k1            o                                                  C
5872 C         (I)          (II)                (III)          (IV)                 C
5873 C                                                                              C
5874 C      eello5_1        eello5_2            eello5_3       eello5_4             C
5875 C                                                                              C
5876 C o denotes a local interaction, vertical lines an electrostatic interaction.  C
5877 C                                                                              C
5878 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
5879 cd      if (i.ne.2 .or. j.ne.6 .or. k.ne.3 .or. l.ne.5) then
5880 cd        eello5=0.0d0
5881 cd        return
5882 cd      endif
5883 cd      write (iout,*)
5884 cd     &   'EELLO5: Contacts have occurred for peptide groups',i,j,
5885 cd     &   ' and',k,l
5886       itk=itortyp(itype(k))
5887       itl=itortyp(itype(l))
5888       itj=itortyp(itype(j))
5889       eello5_1=0.0d0
5890       eello5_2=0.0d0
5891       eello5_3=0.0d0
5892       eello5_4=0.0d0
5893 cd      call checkint5(i,j,k,l,jj,kk,eel5_1_num,eel5_2_num,
5894 cd     &   eel5_3_num,eel5_4_num)
5895       do iii=1,2
5896         do kkk=1,5
5897           do lll=1,3
5898             derx(lll,kkk,iii)=0.0d0
5899           enddo
5900         enddo
5901       enddo
5902 cd      eij=facont_hb(jj,i)
5903 cd      ekl=facont_hb(kk,k)
5904 cd      ekont=eij*ekl
5905 cd      write (iout,*)'Contacts have occurred for peptide groups',
5906 cd     &  i,j,' fcont:',eij,' eij',' and ',k,l
5907 cd      goto 1111
5908 C Contribution from the graph I.
5909 cd      write (2,*) 'AEA  ',AEA(1,1,1),AEA(2,1,1),AEA(1,2,1),AEA(2,2,1)
5910 cd      write (2,*) 'AEAb2',AEAb2(1,1,1),AEAb2(2,1,1)
5911       call transpose2(EUg(1,1,k),auxmat(1,1))
5912       call matmat2(AEA(1,1,1),auxmat(1,1),pizda(1,1))
5913       vv(1)=pizda(1,1)-pizda(2,2)
5914       vv(2)=pizda(1,2)+pizda(2,1)
5915       eello5_1=scalar2(AEAb2(1,1,1),Ub2(1,k))
5916      & +0.5d0*scalar2(vv(1),Dtobr2(1,i))
5917       if (calc_grad) then
5918 C Explicit gradient in virtual-dihedral angles.
5919       if (i.gt.1) g_corr5_loc(i-1)=g_corr5_loc(i-1)
5920      & +ekont*(scalar2(AEAb2derg(1,2,1,1),Ub2(1,k))
5921      & +0.5d0*scalar2(vv(1),Dtobr2der(1,i)))
5922       call transpose2(EUgder(1,1,k),auxmat1(1,1))
5923       call matmat2(AEA(1,1,1),auxmat1(1,1),pizda(1,1))
5924       vv(1)=pizda(1,1)-pizda(2,2)
5925       vv(2)=pizda(1,2)+pizda(2,1)
5926       g_corr5_loc(k-1)=g_corr5_loc(k-1)
5927      & +ekont*(scalar2(AEAb2(1,1,1),Ub2der(1,k))
5928      & +0.5d0*scalar2(vv(1),Dtobr2(1,i)))
5929       call matmat2(AEAderg(1,1,1),auxmat(1,1),pizda(1,1))
5930       vv(1)=pizda(1,1)-pizda(2,2)
5931       vv(2)=pizda(1,2)+pizda(2,1)
5932       if (l.eq.j+1) then
5933         if (l.lt.nres-1) g_corr5_loc(l-1)=g_corr5_loc(l-1)
5934      &   +ekont*(scalar2(AEAb2derg(1,1,1,1),Ub2(1,k))
5935      &   +0.5d0*scalar2(vv(1),Dtobr2(1,i)))
5936       else
5937         if (j.lt.nres-1) g_corr5_loc(j-1)=g_corr5_loc(j-1)
5938      &   +ekont*(scalar2(AEAb2derg(1,1,1,1),Ub2(1,k))
5939      &   +0.5d0*scalar2(vv(1),Dtobr2(1,i)))
5940       endif 
5941 C Cartesian gradient
5942       do iii=1,2
5943         do kkk=1,5
5944           do lll=1,3
5945             call matmat2(AEAderx(1,1,lll,kkk,iii,1),auxmat(1,1),
5946      &        pizda(1,1))
5947             vv(1)=pizda(1,1)-pizda(2,2)
5948             vv(2)=pizda(1,2)+pizda(2,1)
5949             derx(lll,kkk,iii)=derx(lll,kkk,iii)
5950      &       +scalar2(AEAb2derx(1,lll,kkk,iii,1,1),Ub2(1,k))
5951      &       +0.5d0*scalar2(vv(1),Dtobr2(1,i))
5952           enddo
5953         enddo
5954       enddo
5955 c      goto 1112
5956       endif
5957 c1111  continue
5958 C Contribution from graph II 
5959       call transpose2(EE(1,1,itk),auxmat(1,1))
5960       call matmat2(auxmat(1,1),AEA(1,1,1),pizda(1,1))
5961       vv(1)=pizda(1,1)+pizda(2,2)
5962       vv(2)=pizda(2,1)-pizda(1,2)
5963       eello5_2=scalar2(AEAb1(1,2,1),b1(1,itk))
5964      & -0.5d0*scalar2(vv(1),Ctobr(1,k))
5965       if (calc_grad) then
5966 C Explicit gradient in virtual-dihedral angles.
5967       g_corr5_loc(k-1)=g_corr5_loc(k-1)
5968      & -0.5d0*ekont*scalar2(vv(1),Ctobrder(1,k))
5969       call matmat2(auxmat(1,1),AEAderg(1,1,1),pizda(1,1))
5970       vv(1)=pizda(1,1)+pizda(2,2)
5971       vv(2)=pizda(2,1)-pizda(1,2)
5972       if (l.eq.j+1) then
5973         g_corr5_loc(l-1)=g_corr5_loc(l-1)
5974      &   +ekont*(scalar2(AEAb1derg(1,2,1),b1(1,itk))
5975      &   -0.5d0*scalar2(vv(1),Ctobr(1,k)))
5976       else
5977         g_corr5_loc(j-1)=g_corr5_loc(j-1)
5978      &   +ekont*(scalar2(AEAb1derg(1,2,1),b1(1,itk))
5979      &   -0.5d0*scalar2(vv(1),Ctobr(1,k)))
5980       endif
5981 C Cartesian gradient
5982       do iii=1,2
5983         do kkk=1,5
5984           do lll=1,3
5985             call matmat2(auxmat(1,1),AEAderx(1,1,lll,kkk,iii,1),
5986      &        pizda(1,1))
5987             vv(1)=pizda(1,1)+pizda(2,2)
5988             vv(2)=pizda(2,1)-pizda(1,2)
5989             derx(lll,kkk,iii)=derx(lll,kkk,iii)
5990      &       +scalar2(AEAb1derx(1,lll,kkk,iii,2,1),b1(1,itk))
5991      &       -0.5d0*scalar2(vv(1),Ctobr(1,k))
5992           enddo
5993         enddo
5994       enddo
5995 cd      goto 1112
5996       endif
5997 cd1111  continue
5998       if (l.eq.j+1) then
5999 cd        goto 1110
6000 C Parallel orientation
6001 C Contribution from graph III
6002         call transpose2(EUg(1,1,l),auxmat(1,1))
6003         call matmat2(AEA(1,1,2),auxmat(1,1),pizda(1,1))
6004         vv(1)=pizda(1,1)-pizda(2,2)
6005         vv(2)=pizda(1,2)+pizda(2,1)
6006         eello5_3=scalar2(AEAb2(1,1,2),Ub2(1,l))
6007      &   +0.5d0*scalar2(vv(1),Dtobr2(1,j))
6008         if (calc_grad) then
6009 C Explicit gradient in virtual-dihedral angles.
6010         g_corr5_loc(j-1)=g_corr5_loc(j-1)
6011      &   +ekont*(scalar2(AEAb2derg(1,2,1,2),Ub2(1,l))
6012      &   +0.5d0*scalar2(vv(1),Dtobr2der(1,j)))
6013         call matmat2(AEAderg(1,1,2),auxmat(1,1),pizda(1,1))
6014         vv(1)=pizda(1,1)-pizda(2,2)
6015         vv(2)=pizda(1,2)+pizda(2,1)
6016         g_corr5_loc(k-1)=g_corr5_loc(k-1)
6017      &   +ekont*(scalar2(AEAb2derg(1,1,1,2),Ub2(1,l))
6018      &   +0.5d0*scalar2(vv(1),Dtobr2(1,j)))
6019         call transpose2(EUgder(1,1,l),auxmat1(1,1))
6020         call matmat2(AEA(1,1,2),auxmat1(1,1),pizda(1,1))
6021         vv(1)=pizda(1,1)-pizda(2,2)
6022         vv(2)=pizda(1,2)+pizda(2,1)
6023         g_corr5_loc(l-1)=g_corr5_loc(l-1)
6024      &   +ekont*(scalar2(AEAb2(1,1,2),Ub2der(1,l))
6025      &   +0.5d0*scalar2(vv(1),Dtobr2(1,j)))
6026 C Cartesian gradient
6027         do iii=1,2
6028           do kkk=1,5
6029             do lll=1,3
6030               call matmat2(AEAderx(1,1,lll,kkk,iii,2),auxmat(1,1),
6031      &          pizda(1,1))
6032               vv(1)=pizda(1,1)-pizda(2,2)
6033               vv(2)=pizda(1,2)+pizda(2,1)
6034               derx(lll,kkk,iii)=derx(lll,kkk,iii)
6035      &         +scalar2(AEAb2derx(1,lll,kkk,iii,1,2),Ub2(1,l))
6036      &         +0.5d0*scalar2(vv(1),Dtobr2(1,j))
6037             enddo
6038           enddo
6039         enddo
6040 cd        goto 1112
6041         endif
6042 C Contribution from graph IV
6043 cd1110    continue
6044         call transpose2(EE(1,1,itl),auxmat(1,1))
6045         call matmat2(auxmat(1,1),AEA(1,1,2),pizda(1,1))
6046         vv(1)=pizda(1,1)+pizda(2,2)
6047         vv(2)=pizda(2,1)-pizda(1,2)
6048         eello5_4=scalar2(AEAb1(1,2,2),b1(1,itl))
6049      &   -0.5d0*scalar2(vv(1),Ctobr(1,l))
6050         if (calc_grad) then
6051 C Explicit gradient in virtual-dihedral angles.
6052         g_corr5_loc(l-1)=g_corr5_loc(l-1)
6053      &   -0.5d0*ekont*scalar2(vv(1),Ctobrder(1,l))
6054         call matmat2(auxmat(1,1),AEAderg(1,1,2),pizda(1,1))
6055         vv(1)=pizda(1,1)+pizda(2,2)
6056         vv(2)=pizda(2,1)-pizda(1,2)
6057         g_corr5_loc(k-1)=g_corr5_loc(k-1)
6058      &   +ekont*(scalar2(AEAb1derg(1,2,2),b1(1,itl))
6059      &   -0.5d0*scalar2(vv(1),Ctobr(1,l)))
6060 C Cartesian gradient
6061         do iii=1,2
6062           do kkk=1,5
6063             do lll=1,3
6064               call matmat2(auxmat(1,1),AEAderx(1,1,lll,kkk,iii,2),
6065      &          pizda(1,1))
6066               vv(1)=pizda(1,1)+pizda(2,2)
6067               vv(2)=pizda(2,1)-pizda(1,2)
6068               derx(lll,kkk,iii)=derx(lll,kkk,iii)
6069      &         +scalar2(AEAb1derx(1,lll,kkk,iii,2,2),b1(1,itl))
6070      &         -0.5d0*scalar2(vv(1),Ctobr(1,l))
6071             enddo
6072           enddo
6073         enddo
6074         endif
6075       else
6076 C Antiparallel orientation
6077 C Contribution from graph III
6078 c        goto 1110
6079         call transpose2(EUg(1,1,j),auxmat(1,1))
6080         call matmat2(AEA(1,1,2),auxmat(1,1),pizda(1,1))
6081         vv(1)=pizda(1,1)-pizda(2,2)
6082         vv(2)=pizda(1,2)+pizda(2,1)
6083         eello5_3=scalar2(AEAb2(1,1,2),Ub2(1,j))
6084      &   +0.5d0*scalar2(vv(1),Dtobr2(1,l))
6085         if (calc_grad) then
6086 C Explicit gradient in virtual-dihedral angles.
6087         g_corr5_loc(l-1)=g_corr5_loc(l-1)
6088      &   +ekont*(scalar2(AEAb2derg(1,2,1,2),Ub2(1,j))
6089      &   +0.5d0*scalar2(vv(1),Dtobr2der(1,l)))
6090         call matmat2(AEAderg(1,1,2),auxmat(1,1),pizda(1,1))
6091         vv(1)=pizda(1,1)-pizda(2,2)
6092         vv(2)=pizda(1,2)+pizda(2,1)
6093         g_corr5_loc(k-1)=g_corr5_loc(k-1)
6094      &   +ekont*(scalar2(AEAb2derg(1,1,1,2),Ub2(1,j))
6095      &   +0.5d0*scalar2(vv(1),Dtobr2(1,l)))
6096         call transpose2(EUgder(1,1,j),auxmat1(1,1))
6097         call matmat2(AEA(1,1,2),auxmat1(1,1),pizda(1,1))
6098         vv(1)=pizda(1,1)-pizda(2,2)
6099         vv(2)=pizda(1,2)+pizda(2,1)
6100         g_corr5_loc(j-1)=g_corr5_loc(j-1)
6101      &   +ekont*(scalar2(AEAb2(1,1,2),Ub2der(1,j))
6102      &   +0.5d0*scalar2(vv(1),Dtobr2(1,l)))
6103 C Cartesian gradient
6104         do iii=1,2
6105           do kkk=1,5
6106             do lll=1,3
6107               call matmat2(AEAderx(1,1,lll,kkk,iii,2),auxmat(1,1),
6108      &          pizda(1,1))
6109               vv(1)=pizda(1,1)-pizda(2,2)
6110               vv(2)=pizda(1,2)+pizda(2,1)
6111               derx(lll,kkk,3-iii)=derx(lll,kkk,3-iii)
6112      &         +scalar2(AEAb2derx(1,lll,kkk,iii,1,2),Ub2(1,j))
6113      &         +0.5d0*scalar2(vv(1),Dtobr2(1,l))
6114             enddo
6115           enddo
6116         enddo
6117 cd        goto 1112
6118         endif
6119 C Contribution from graph IV
6120 1110    continue
6121         call transpose2(EE(1,1,itj),auxmat(1,1))
6122         call matmat2(auxmat(1,1),AEA(1,1,2),pizda(1,1))
6123         vv(1)=pizda(1,1)+pizda(2,2)
6124         vv(2)=pizda(2,1)-pizda(1,2)
6125         eello5_4=scalar2(AEAb1(1,2,2),b1(1,itj))
6126      &   -0.5d0*scalar2(vv(1),Ctobr(1,j))
6127         if (calc_grad) then
6128 C Explicit gradient in virtual-dihedral angles.
6129         g_corr5_loc(j-1)=g_corr5_loc(j-1)
6130      &   -0.5d0*ekont*scalar2(vv(1),Ctobrder(1,j))
6131         call matmat2(auxmat(1,1),AEAderg(1,1,2),pizda(1,1))
6132         vv(1)=pizda(1,1)+pizda(2,2)
6133         vv(2)=pizda(2,1)-pizda(1,2)
6134         g_corr5_loc(k-1)=g_corr5_loc(k-1)
6135      &   +ekont*(scalar2(AEAb1derg(1,2,2),b1(1,itj))
6136      &   -0.5d0*scalar2(vv(1),Ctobr(1,j)))
6137 C Cartesian gradient
6138         do iii=1,2
6139           do kkk=1,5
6140             do lll=1,3
6141               call matmat2(auxmat(1,1),AEAderx(1,1,lll,kkk,iii,2),
6142      &          pizda(1,1))
6143               vv(1)=pizda(1,1)+pizda(2,2)
6144               vv(2)=pizda(2,1)-pizda(1,2)
6145               derx(lll,kkk,3-iii)=derx(lll,kkk,3-iii)
6146      &         +scalar2(AEAb1derx(1,lll,kkk,iii,2,2),b1(1,itj))
6147      &         -0.5d0*scalar2(vv(1),Ctobr(1,j))
6148             enddo
6149           enddo
6150         enddo
6151       endif
6152       endif
6153 1112  continue
6154       eel5=eello5_1+eello5_2+eello5_3+eello5_4
6155 cd      if (i.eq.2 .and. j.eq.8 .and. k.eq.3 .and. l.eq.7) then
6156 cd        write (2,*) 'ijkl',i,j,k,l
6157 cd        write (2,*) 'eello5_1',eello5_1,' eello5_2',eello5_2,
6158 cd     &     ' eello5_3',eello5_3,' eello5_4',eello5_4
6159 cd      endif
6160 cd      write(iout,*) 'eello5_1',eello5_1,' eel5_1_num',16*eel5_1_num
6161 cd      write(iout,*) 'eello5_2',eello5_2,' eel5_2_num',16*eel5_2_num
6162 cd      write(iout,*) 'eello5_3',eello5_3,' eel5_3_num',16*eel5_3_num
6163 cd      write(iout,*) 'eello5_4',eello5_4,' eel5_4_num',16*eel5_4_num
6164       if (calc_grad) then
6165       if (j.lt.nres-1) then
6166         j1=j+1
6167         j2=j-1
6168       else
6169         j1=j-1
6170         j2=j-2
6171       endif
6172       if (l.lt.nres-1) then
6173         l1=l+1
6174         l2=l-1
6175       else
6176         l1=l-1
6177         l2=l-2
6178       endif
6179 cd      eij=1.0d0
6180 cd      ekl=1.0d0
6181 cd      ekont=1.0d0
6182 cd      write (2,*) 'eij',eij,' ekl',ekl,' ekont',ekont
6183       do ll=1,3
6184         ggg1(ll)=eel5*g_contij(ll,1)
6185         ggg2(ll)=eel5*g_contij(ll,2)
6186 cold        ghalf=0.5d0*eel5*ekl*gacont_hbr(ll,jj,i)
6187         ghalf=0.5d0*ggg1(ll)
6188 cd        ghalf=0.0d0
6189         gradcorr5(ll,i)=gradcorr5(ll,i)+ghalf+ekont*derx(ll,2,1)
6190         gradcorr5(ll,i+1)=gradcorr5(ll,i+1)+ekont*derx(ll,3,1)
6191         gradcorr5(ll,j)=gradcorr5(ll,j)+ghalf+ekont*derx(ll,4,1)
6192         gradcorr5(ll,j1)=gradcorr5(ll,j1)+ekont*derx(ll,5,1)
6193 cold        ghalf=0.5d0*eel5*eij*gacont_hbr(ll,kk,k)
6194         ghalf=0.5d0*ggg2(ll)
6195 cd        ghalf=0.0d0
6196         gradcorr5(ll,k)=gradcorr5(ll,k)+ghalf+ekont*derx(ll,2,2)
6197         gradcorr5(ll,k+1)=gradcorr5(ll,k+1)+ekont*derx(ll,3,2)
6198         gradcorr5(ll,l)=gradcorr5(ll,l)+ghalf+ekont*derx(ll,4,2)
6199         gradcorr5(ll,l1)=gradcorr5(ll,l1)+ekont*derx(ll,5,2)
6200       enddo
6201 cd      goto 1112
6202       do m=i+1,j-1
6203         do ll=1,3
6204 cold          gradcorr5(ll,m)=gradcorr5(ll,m)+eel5*ekl*gacont_hbr(ll,jj,i)
6205           gradcorr5(ll,m)=gradcorr5(ll,m)+ggg1(ll)
6206         enddo
6207       enddo
6208       do m=k+1,l-1
6209         do ll=1,3
6210 cold          gradcorr5(ll,m)=gradcorr5(ll,m)+eel5*eij*gacont_hbr(ll,kk,k)
6211           gradcorr5(ll,m)=gradcorr5(ll,m)+ggg2(ll)
6212         enddo
6213       enddo
6214 c1112  continue
6215       do m=i+2,j2
6216         do ll=1,3
6217           gradcorr5(ll,m)=gradcorr5(ll,m)+ekont*derx(ll,1,1)
6218         enddo
6219       enddo
6220       do m=k+2,l2
6221         do ll=1,3
6222           gradcorr5(ll,m)=gradcorr5(ll,m)+ekont*derx(ll,1,2)
6223         enddo
6224       enddo 
6225 cd      do iii=1,nres-3
6226 cd        write (2,*) iii,g_corr5_loc(iii)
6227 cd      enddo
6228       endif
6229       eello5=ekont*eel5
6230 cd      write (2,*) 'ekont',ekont
6231 cd      write (iout,*) 'eello5',ekont*eel5
6232       return
6233       end
6234 c--------------------------------------------------------------------------
6235       double precision function eello6(i,j,k,l,jj,kk)
6236       implicit real*8 (a-h,o-z)
6237       include 'DIMENSIONS'
6238       include 'DIMENSIONS.ZSCOPT'
6239       include 'COMMON.IOUNITS'
6240       include 'COMMON.CHAIN'
6241       include 'COMMON.DERIV'
6242       include 'COMMON.INTERACT'
6243       include 'COMMON.CONTACTS'
6244       include 'COMMON.TORSION'
6245       include 'COMMON.VAR'
6246       include 'COMMON.GEO'
6247       include 'COMMON.FFIELD'
6248       double precision ggg1(3),ggg2(3)
6249 cd      if (i.ne.1 .or. j.ne.3 .or. k.ne.2 .or. l.ne.4) then
6250 cd        eello6=0.0d0
6251 cd        return
6252 cd      endif
6253 cd      write (iout,*)
6254 cd     &   'EELLO6: Contacts have occurred for peptide groups',i,j,
6255 cd     &   ' and',k,l
6256       eello6_1=0.0d0
6257       eello6_2=0.0d0
6258       eello6_3=0.0d0
6259       eello6_4=0.0d0
6260       eello6_5=0.0d0
6261       eello6_6=0.0d0
6262 cd      call checkint6(i,j,k,l,jj,kk,eel6_1_num,eel6_2_num,
6263 cd     &   eel6_3_num,eel6_4_num,eel6_5_num,eel6_6_num)
6264       do iii=1,2
6265         do kkk=1,5
6266           do lll=1,3
6267             derx(lll,kkk,iii)=0.0d0
6268           enddo
6269         enddo
6270       enddo
6271 cd      eij=facont_hb(jj,i)
6272 cd      ekl=facont_hb(kk,k)
6273 cd      ekont=eij*ekl
6274 cd      eij=1.0d0
6275 cd      ekl=1.0d0
6276 cd      ekont=1.0d0
6277       if (l.eq.j+1) then
6278         eello6_1=eello6_graph1(i,j,k,l,1,.false.)
6279         eello6_2=eello6_graph1(j,i,l,k,2,.false.)
6280         eello6_3=eello6_graph2(i,j,k,l,jj,kk,.false.)
6281         eello6_4=eello6_graph4(i,j,k,l,jj,kk,1,.false.)
6282         eello6_5=eello6_graph4(j,i,l,k,jj,kk,2,.false.)
6283         eello6_6=eello6_graph3(i,j,k,l,jj,kk,.false.)
6284       else
6285         eello6_1=eello6_graph1(i,j,k,l,1,.false.)
6286         eello6_2=eello6_graph1(l,k,j,i,2,.true.)
6287         eello6_3=eello6_graph2(i,l,k,j,jj,kk,.true.)
6288         eello6_4=eello6_graph4(i,j,k,l,jj,kk,1,.false.)
6289         if (wturn6.eq.0.0d0 .or. j.ne.i+4) then
6290           eello6_5=eello6_graph4(l,k,j,i,kk,jj,2,.true.)
6291         else
6292           eello6_5=0.0d0
6293         endif
6294         eello6_6=eello6_graph3(i,l,k,j,jj,kk,.true.)
6295       endif
6296 C If turn contributions are considered, they will be handled separately.
6297       eel6=eello6_1+eello6_2+eello6_3+eello6_4+eello6_5+eello6_6
6298 cd      write(iout,*) 'eello6_1',eello6_1,' eel6_1_num',16*eel6_1_num
6299 cd      write(iout,*) 'eello6_2',eello6_2,' eel6_2_num',16*eel6_2_num
6300 cd      write(iout,*) 'eello6_3',eello6_3,' eel6_3_num',16*eel6_3_num
6301 cd      write(iout,*) 'eello6_4',eello6_4,' eel6_4_num',16*eel6_4_num
6302 cd      write(iout,*) 'eello6_5',eello6_5,' eel6_5_num',16*eel6_5_num
6303 cd      write(iout,*) 'eello6_6',eello6_6,' eel6_6_num',16*eel6_6_num
6304 cd      goto 1112
6305       if (calc_grad) then
6306       if (j.lt.nres-1) then
6307         j1=j+1
6308         j2=j-1
6309       else
6310         j1=j-1
6311         j2=j-2
6312       endif
6313       if (l.lt.nres-1) then
6314         l1=l+1
6315         l2=l-1
6316       else
6317         l1=l-1
6318         l2=l-2
6319       endif
6320       do ll=1,3
6321         ggg1(ll)=eel6*g_contij(ll,1)
6322         ggg2(ll)=eel6*g_contij(ll,2)
6323 cold        ghalf=0.5d0*eel6*ekl*gacont_hbr(ll,jj,i)
6324         ghalf=0.5d0*ggg1(ll)
6325 cd        ghalf=0.0d0
6326         gradcorr6(ll,i)=gradcorr6(ll,i)+ghalf+ekont*derx(ll,2,1)
6327         gradcorr6(ll,i+1)=gradcorr6(ll,i+1)+ekont*derx(ll,3,1)
6328         gradcorr6(ll,j)=gradcorr6(ll,j)+ghalf+ekont*derx(ll,4,1)
6329         gradcorr6(ll,j1)=gradcorr6(ll,j1)+ekont*derx(ll,5,1)
6330         ghalf=0.5d0*ggg2(ll)
6331 cold        ghalf=0.5d0*eel6*eij*gacont_hbr(ll,kk,k)
6332 cd        ghalf=0.0d0
6333         gradcorr6(ll,k)=gradcorr6(ll,k)+ghalf+ekont*derx(ll,2,2)
6334         gradcorr6(ll,k+1)=gradcorr6(ll,k+1)+ekont*derx(ll,3,2)
6335         gradcorr6(ll,l)=gradcorr6(ll,l)+ghalf+ekont*derx(ll,4,2)
6336         gradcorr6(ll,l1)=gradcorr6(ll,l1)+ekont*derx(ll,5,2)
6337       enddo
6338 cd      goto 1112
6339       do m=i+1,j-1
6340         do ll=1,3
6341 cold          gradcorr6(ll,m)=gradcorr6(ll,m)+eel6*ekl*gacont_hbr(ll,jj,i)
6342           gradcorr6(ll,m)=gradcorr6(ll,m)+ggg1(ll)
6343         enddo
6344       enddo
6345       do m=k+1,l-1
6346         do ll=1,3
6347 cold          gradcorr6(ll,m)=gradcorr6(ll,m)+eel6*eij*gacont_hbr(ll,kk,k)
6348           gradcorr6(ll,m)=gradcorr6(ll,m)+ggg2(ll)
6349         enddo
6350       enddo
6351 1112  continue
6352       do m=i+2,j2
6353         do ll=1,3
6354           gradcorr6(ll,m)=gradcorr6(ll,m)+ekont*derx(ll,1,1)
6355         enddo
6356       enddo
6357       do m=k+2,l2
6358         do ll=1,3
6359           gradcorr6(ll,m)=gradcorr6(ll,m)+ekont*derx(ll,1,2)
6360         enddo
6361       enddo 
6362 cd      do iii=1,nres-3
6363 cd        write (2,*) iii,g_corr6_loc(iii)
6364 cd      enddo
6365       endif
6366       eello6=ekont*eel6
6367 cd      write (2,*) 'ekont',ekont
6368 cd      write (iout,*) 'eello6',ekont*eel6
6369       return
6370       end
6371 c--------------------------------------------------------------------------
6372       double precision function eello6_graph1(i,j,k,l,imat,swap)
6373       implicit real*8 (a-h,o-z)
6374       include 'DIMENSIONS'
6375       include 'DIMENSIONS.ZSCOPT'
6376       include 'COMMON.IOUNITS'
6377       include 'COMMON.CHAIN'
6378       include 'COMMON.DERIV'
6379       include 'COMMON.INTERACT'
6380       include 'COMMON.CONTACTS'
6381       include 'COMMON.TORSION'
6382       include 'COMMON.VAR'
6383       include 'COMMON.GEO'
6384       double precision vv(2),vv1(2),pizda(2,2),auxmat(2,2),pizda1(2,2)
6385       logical swap
6386       logical lprn
6387       common /kutas/ lprn
6388 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
6389 C                                                                              C
6390 C      Parallel       Antiparallel                                             C
6391 C                                                                              C
6392 C          o             o                                                     C
6393 C         /l\           /j\                                                    C 
6394 C        /   \         /   \                                                   C
6395 C       /| o |         | o |\                                                  C
6396 C     \ j|/k\|  /   \  |/k\|l /                                                C
6397 C      \ /   \ /     \ /   \ /                                                 C
6398 C       o     o       o     o                                                  C
6399 C       i             i                                                        C
6400 C                                                                              C
6401 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
6402       itk=itortyp(itype(k))
6403       s1= scalar2(AEAb1(1,2,imat),CUgb2(1,i))
6404       s2=-scalar2(AEAb2(1,1,imat),Ug2Db1t(1,k))
6405       s3= scalar2(AEAb2(1,1,imat),CUgb2(1,k))
6406       call transpose2(EUgC(1,1,k),auxmat(1,1))
6407       call matmat2(AEA(1,1,imat),auxmat(1,1),pizda1(1,1))
6408       vv1(1)=pizda1(1,1)-pizda1(2,2)
6409       vv1(2)=pizda1(1,2)+pizda1(2,1)
6410       s4=0.5d0*scalar2(vv1(1),Dtobr2(1,i))
6411       vv(1)=AEAb1(1,2,imat)*b1(1,itk)-AEAb1(2,2,imat)*b1(2,itk)
6412       vv(2)=AEAb1(1,2,imat)*b1(2,itk)+AEAb1(2,2,imat)*b1(1,itk)
6413       s5=scalar2(vv(1),Dtobr2(1,i))
6414 cd      write (2,*) 's1',s1,' s2',s2,' s3',s3,' s4', s4,' s5',s5
6415       eello6_graph1=-0.5d0*(s1+s2+s3+s4+s5)
6416       if (.not. calc_grad) return
6417       if (i.gt.1) g_corr6_loc(i-1)=g_corr6_loc(i-1)
6418      & -0.5d0*ekont*(scalar2(AEAb1(1,2,imat),CUgb2der(1,i))
6419      & -scalar2(AEAb2derg(1,2,1,imat),Ug2Db1t(1,k))
6420      & +scalar2(AEAb2derg(1,2,1,imat),CUgb2(1,k))
6421      & +0.5d0*scalar2(vv1(1),Dtobr2der(1,i))
6422      & +scalar2(vv(1),Dtobr2der(1,i)))
6423       call matmat2(AEAderg(1,1,imat),auxmat(1,1),pizda1(1,1))
6424       vv1(1)=pizda1(1,1)-pizda1(2,2)
6425       vv1(2)=pizda1(1,2)+pizda1(2,1)
6426       vv(1)=AEAb1derg(1,2,imat)*b1(1,itk)-AEAb1derg(2,2,imat)*b1(2,itk)
6427       vv(2)=AEAb1derg(1,2,imat)*b1(2,itk)+AEAb1derg(2,2,imat)*b1(1,itk)
6428       if (l.eq.j+1) then
6429         g_corr6_loc(l-1)=g_corr6_loc(l-1)
6430      & +ekont*(-0.5d0*(scalar2(AEAb1derg(1,2,imat),CUgb2(1,i))
6431      & -scalar2(AEAb2derg(1,1,1,imat),Ug2Db1t(1,k))
6432      & +scalar2(AEAb2derg(1,1,1,imat),CUgb2(1,k))
6433      & +0.5d0*scalar2(vv1(1),Dtobr2(1,i))+scalar2(vv(1),Dtobr2(1,i))))
6434       else
6435         g_corr6_loc(j-1)=g_corr6_loc(j-1)
6436      & +ekont*(-0.5d0*(scalar2(AEAb1derg(1,2,imat),CUgb2(1,i))
6437      & -scalar2(AEAb2derg(1,1,1,imat),Ug2Db1t(1,k))
6438      & +scalar2(AEAb2derg(1,1,1,imat),CUgb2(1,k))
6439      & +0.5d0*scalar2(vv1(1),Dtobr2(1,i))+scalar2(vv(1),Dtobr2(1,i))))
6440       endif
6441       call transpose2(EUgCder(1,1,k),auxmat(1,1))
6442       call matmat2(AEA(1,1,imat),auxmat(1,1),pizda1(1,1))
6443       vv1(1)=pizda1(1,1)-pizda1(2,2)
6444       vv1(2)=pizda1(1,2)+pizda1(2,1)
6445       if (k.gt.1) g_corr6_loc(k-1)=g_corr6_loc(k-1)
6446      & +ekont*(-0.5d0*(-scalar2(AEAb2(1,1,imat),Ug2Db1tder(1,k))
6447      & +scalar2(AEAb2(1,1,imat),CUgb2der(1,k))
6448      & +0.5d0*scalar2(vv1(1),Dtobr2(1,i))))
6449       do iii=1,2
6450         if (swap) then
6451           ind=3-iii
6452         else
6453           ind=iii
6454         endif
6455         do kkk=1,5
6456           do lll=1,3
6457             s1= scalar2(AEAb1derx(1,lll,kkk,iii,2,imat),CUgb2(1,i))
6458             s2=-scalar2(AEAb2derx(1,lll,kkk,iii,1,imat),Ug2Db1t(1,k))
6459             s3= scalar2(AEAb2derx(1,lll,kkk,iii,1,imat),CUgb2(1,k))
6460             call transpose2(EUgC(1,1,k),auxmat(1,1))
6461             call matmat2(AEAderx(1,1,lll,kkk,iii,imat),auxmat(1,1),
6462      &        pizda1(1,1))
6463             vv1(1)=pizda1(1,1)-pizda1(2,2)
6464             vv1(2)=pizda1(1,2)+pizda1(2,1)
6465             s4=0.5d0*scalar2(vv1(1),Dtobr2(1,i))
6466             vv(1)=AEAb1derx(1,lll,kkk,iii,2,imat)*b1(1,itk)
6467      &       -AEAb1derx(2,lll,kkk,iii,2,imat)*b1(2,itk)
6468             vv(2)=AEAb1derx(1,lll,kkk,iii,2,imat)*b1(2,itk)
6469      &       +AEAb1derx(2,lll,kkk,iii,2,imat)*b1(1,itk)
6470             s5=scalar2(vv(1),Dtobr2(1,i))
6471             derx(lll,kkk,ind)=derx(lll,kkk,ind)-0.5d0*(s1+s2+s3+s4+s5)
6472           enddo
6473         enddo
6474       enddo
6475       return
6476       end
6477 c----------------------------------------------------------------------------
6478       double precision function eello6_graph2(i,j,k,l,jj,kk,swap)
6479       implicit real*8 (a-h,o-z)
6480       include 'DIMENSIONS'
6481       include 'DIMENSIONS.ZSCOPT'
6482       include 'COMMON.IOUNITS'
6483       include 'COMMON.CHAIN'
6484       include 'COMMON.DERIV'
6485       include 'COMMON.INTERACT'
6486       include 'COMMON.CONTACTS'
6487       include 'COMMON.TORSION'
6488       include 'COMMON.VAR'
6489       include 'COMMON.GEO'
6490       logical swap
6491       double precision vv(2),pizda(2,2),auxmat(2,2),auxvec(2),
6492      & auxvec1(2),auxvec2(2),auxmat1(2,2)
6493       logical lprn
6494       common /kutas/ lprn
6495 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
6496 C                                                                              C 
6497 C      Parallel       Antiparallel                                             C
6498 C                                                                              C
6499 C          o             o                                                     C
6500 C     \   /l\           /j\   /                                                C
6501 C      \ /   \         /   \ /                                                 C
6502 C       o| o |         | o |o                                                  C
6503 C     \ j|/k\|      \  |/k\|l                                                  C
6504 C      \ /   \       \ /   \                                                   C
6505 C       o             o                                                        C
6506 C       i             i                                                        C
6507 C                                                                              C
6508 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
6509 cd      write (2,*) 'eello6_graph2: i,',i,' j',j,' k',k,' l',l
6510 C AL 7/4/01 s1 would occur in the sixth-order moment, 
6511 C           but not in a cluster cumulant
6512 #ifdef MOMENT
6513       s1=dip(1,jj,i)*dip(1,kk,k)
6514 #endif
6515       call matvec2(ADtEA1(1,1,1),Ub2(1,k),auxvec(1))
6516       s2=-0.5d0*scalar2(Ub2(1,i),auxvec(1))
6517       call matvec2(ADtEA(1,1,2),Ub2(1,l),auxvec1(1))
6518       s3=-0.5d0*scalar2(Ub2(1,j),auxvec1(1))
6519       call transpose2(EUg(1,1,k),auxmat(1,1))
6520       call matmat2(ADtEA1(1,1,1),auxmat(1,1),pizda(1,1))
6521       vv(1)=pizda(1,1)-pizda(2,2)
6522       vv(2)=pizda(1,2)+pizda(2,1)
6523       s4=-0.25d0*scalar2(vv(1),Dtobr2(1,i))
6524 cd      write (2,*) 'eello6_graph2:','s1',s1,' s2',s2,' s3',s3,' s4',s4
6525 #ifdef MOMENT
6526       eello6_graph2=-(s1+s2+s3+s4)
6527 #else
6528       eello6_graph2=-(s2+s3+s4)
6529 #endif
6530 c      eello6_graph2=-s3
6531       if (.not. calc_grad) return
6532 C Derivatives in gamma(i-1)
6533       if (i.gt.1) then
6534 #ifdef MOMENT
6535         s1=dipderg(1,jj,i)*dip(1,kk,k)
6536 #endif
6537         s2=-0.5d0*scalar2(Ub2der(1,i),auxvec(1))
6538         call matvec2(ADtEAderg(1,1,1,2),Ub2(1,l),auxvec2(1))
6539         s3=-0.5d0*scalar2(Ub2(1,j),auxvec2(1))
6540         s4=-0.25d0*scalar2(vv(1),Dtobr2der(1,i))
6541 #ifdef MOMENT
6542         g_corr6_loc(i-1)=g_corr6_loc(i-1)-ekont*(s1+s2+s3+s4)
6543 #else
6544         g_corr6_loc(i-1)=g_corr6_loc(i-1)-ekont*(s2+s3+s4)
6545 #endif
6546 c        g_corr6_loc(i-1)=g_corr6_loc(i-1)-s3
6547       endif
6548 C Derivatives in gamma(k-1)
6549 #ifdef MOMENT
6550       s1=dip(1,jj,i)*dipderg(1,kk,k)
6551 #endif
6552       call matvec2(ADtEA1(1,1,1),Ub2der(1,k),auxvec2(1))
6553       s2=-0.5d0*scalar2(Ub2(1,i),auxvec2(1))
6554       call matvec2(ADtEAderg(1,1,2,2),Ub2(1,l),auxvec2(1))
6555       s3=-0.5d0*scalar2(Ub2(1,j),auxvec2(1))
6556       call transpose2(EUgder(1,1,k),auxmat1(1,1))
6557       call matmat2(ADtEA1(1,1,1),auxmat1(1,1),pizda(1,1))
6558       vv(1)=pizda(1,1)-pizda(2,2)
6559       vv(2)=pizda(1,2)+pizda(2,1)
6560       s4=-0.25d0*scalar2(vv(1),Dtobr2(1,i))
6561 #ifdef MOMENT
6562       g_corr6_loc(k-1)=g_corr6_loc(k-1)-ekont*(s1+s2+s3+s4)
6563 #else
6564       g_corr6_loc(k-1)=g_corr6_loc(k-1)-ekont*(s2+s3+s4)
6565 #endif
6566 c      g_corr6_loc(k-1)=g_corr6_loc(k-1)-s3
6567 C Derivatives in gamma(j-1) or gamma(l-1)
6568       if (j.gt.1) then
6569 #ifdef MOMENT
6570         s1=dipderg(3,jj,i)*dip(1,kk,k) 
6571 #endif
6572         call matvec2(ADtEA1derg(1,1,1,1),Ub2(1,k),auxvec2(1))
6573         s2=-0.5d0*scalar2(Ub2(1,i),auxvec2(1))
6574         s3=-0.5d0*scalar2(Ub2der(1,j),auxvec1(1))
6575         call matmat2(ADtEA1derg(1,1,1,1),auxmat(1,1),pizda(1,1))
6576         vv(1)=pizda(1,1)-pizda(2,2)
6577         vv(2)=pizda(1,2)+pizda(2,1)
6578         s4=-0.25d0*scalar2(vv(1),Dtobr2(1,i))
6579 #ifdef MOMENT
6580         if (swap) then
6581           g_corr6_loc(l-1)=g_corr6_loc(l-1)-ekont*s1
6582         else
6583           g_corr6_loc(j-1)=g_corr6_loc(j-1)-ekont*s1
6584         endif
6585 #endif
6586         g_corr6_loc(j-1)=g_corr6_loc(j-1)-ekont*(s2+s3+s4)
6587 c        g_corr6_loc(j-1)=g_corr6_loc(j-1)-s3
6588       endif
6589 C Derivatives in gamma(l-1) or gamma(j-1)
6590       if (l.gt.1) then 
6591 #ifdef MOMENT
6592         s1=dip(1,jj,i)*dipderg(3,kk,k)
6593 #endif
6594         call matvec2(ADtEA1derg(1,1,2,1),Ub2(1,k),auxvec2(1))
6595         s2=-0.5d0*scalar2(Ub2(1,i),auxvec2(1))
6596         call matvec2(ADtEA(1,1,2),Ub2der(1,l),auxvec2(1))
6597         s3=-0.5d0*scalar2(Ub2(1,j),auxvec2(1))
6598         call matmat2(ADtEA1derg(1,1,2,1),auxmat(1,1),pizda(1,1))
6599         vv(1)=pizda(1,1)-pizda(2,2)
6600         vv(2)=pizda(1,2)+pizda(2,1)
6601         s4=-0.25d0*scalar2(vv(1),Dtobr2(1,i))
6602 #ifdef MOMENT
6603         if (swap) then
6604           g_corr6_loc(j-1)=g_corr6_loc(j-1)-ekont*s1
6605         else
6606           g_corr6_loc(l-1)=g_corr6_loc(l-1)-ekont*s1
6607         endif
6608 #endif
6609         g_corr6_loc(l-1)=g_corr6_loc(l-1)-ekont*(s2+s3+s4)
6610 c        g_corr6_loc(l-1)=g_corr6_loc(l-1)-s3
6611       endif
6612 C Cartesian derivatives.
6613       if (lprn) then
6614         write (2,*) 'In eello6_graph2'
6615         do iii=1,2
6616           write (2,*) 'iii=',iii
6617           do kkk=1,5
6618             write (2,*) 'kkk=',kkk
6619             do jjj=1,2
6620               write (2,'(3(2f10.5),5x)') 
6621      &        ((ADtEA1derx(jjj,mmm,lll,kkk,iii,1),mmm=1,2),lll=1,3)
6622             enddo
6623           enddo
6624         enddo
6625       endif
6626       do iii=1,2
6627         do kkk=1,5
6628           do lll=1,3
6629 #ifdef MOMENT
6630             if (iii.eq.1) then
6631               s1=dipderx(lll,kkk,1,jj,i)*dip(1,kk,k)
6632             else
6633               s1=dip(1,jj,i)*dipderx(lll,kkk,1,kk,k)
6634             endif
6635 #endif
6636             call matvec2(ADtEA1derx(1,1,lll,kkk,iii,1),Ub2(1,k),
6637      &        auxvec(1))
6638             s2=-0.5d0*scalar2(Ub2(1,i),auxvec(1))
6639             call matvec2(ADtEAderx(1,1,lll,kkk,iii,2),Ub2(1,l),
6640      &        auxvec(1))
6641             s3=-0.5d0*scalar2(Ub2(1,j),auxvec(1))
6642             call transpose2(EUg(1,1,k),auxmat(1,1))
6643             call matmat2(ADtEA1derx(1,1,lll,kkk,iii,1),auxmat(1,1),
6644      &        pizda(1,1))
6645             vv(1)=pizda(1,1)-pizda(2,2)
6646             vv(2)=pizda(1,2)+pizda(2,1)
6647             s4=-0.25d0*scalar2(vv(1),Dtobr2(1,i))
6648 cd            write (2,*) 's1',s1,' s2',s2,' s3',s3,' s4',s4
6649 #ifdef MOMENT
6650             derx(lll,kkk,iii)=derx(lll,kkk,iii)-(s1+s2+s4)
6651 #else
6652             derx(lll,kkk,iii)=derx(lll,kkk,iii)-(s2+s4)
6653 #endif
6654             if (swap) then
6655               derx(lll,kkk,3-iii)=derx(lll,kkk,3-iii)-s3
6656             else
6657               derx(lll,kkk,iii)=derx(lll,kkk,iii)-s3
6658             endif
6659           enddo
6660         enddo
6661       enddo
6662       return
6663       end
6664 c----------------------------------------------------------------------------
6665       double precision function eello6_graph3(i,j,k,l,jj,kk,swap)
6666       implicit real*8 (a-h,o-z)
6667       include 'DIMENSIONS'
6668       include 'DIMENSIONS.ZSCOPT'
6669       include 'COMMON.IOUNITS'
6670       include 'COMMON.CHAIN'
6671       include 'COMMON.DERIV'
6672       include 'COMMON.INTERACT'
6673       include 'COMMON.CONTACTS'
6674       include 'COMMON.TORSION'
6675       include 'COMMON.VAR'
6676       include 'COMMON.GEO'
6677       double precision vv(2),pizda(2,2),auxmat(2,2),auxvec(2)
6678       logical swap
6679 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
6680 C                                                                              C
6681 C      Parallel       Antiparallel                                             C
6682 C                                                                              C
6683 C          o             o                                                     C
6684 C         /l\   /   \   /j\                                                    C
6685 C        /   \ /     \ /   \                                                   C
6686 C       /| o |o       o| o |\                                                  C
6687 C       j|/k\|  /      |/k\|l /                                                C
6688 C        /   \ /       /   \ /                                                 C
6689 C       /     o       /     o                                                  C
6690 C       i             i                                                        C
6691 C                                                                              C
6692 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
6693 C
6694 C 4/7/01 AL Component s1 was removed, because it pertains to the respective 
6695 C           energy moment and not to the cluster cumulant.
6696       iti=itortyp(itype(i))
6697       if (j.lt.nres-1) then
6698         itj1=itortyp(itype(j+1))
6699       else
6700         itj1=ntortyp+1
6701       endif
6702       itk=itortyp(itype(k))
6703       itk1=itortyp(itype(k+1))
6704       if (l.lt.nres-1) then
6705         itl1=itortyp(itype(l+1))
6706       else
6707         itl1=ntortyp+1
6708       endif
6709 #ifdef MOMENT
6710       s1=dip(4,jj,i)*dip(4,kk,k)
6711 #endif
6712       call matvec2(AECA(1,1,1),b1(1,itk1),auxvec(1))
6713       s2=0.5d0*scalar2(b1(1,itk),auxvec(1))
6714       call matvec2(AECA(1,1,2),b1(1,itl1),auxvec(1))
6715       s3=0.5d0*scalar2(b1(1,itj1),auxvec(1))
6716       call transpose2(EE(1,1,itk),auxmat(1,1))
6717       call matmat2(auxmat(1,1),AECA(1,1,1),pizda(1,1))
6718       vv(1)=pizda(1,1)+pizda(2,2)
6719       vv(2)=pizda(2,1)-pizda(1,2)
6720       s4=-0.25d0*scalar2(vv(1),Ctobr(1,k))
6721 cd      write (2,*) 'eello6_graph3:','s1',s1,' s2',s2,' s3',s3,' s4',s4
6722 #ifdef MOMENT
6723       eello6_graph3=-(s1+s2+s3+s4)
6724 #else
6725       eello6_graph3=-(s2+s3+s4)
6726 #endif
6727 c      eello6_graph3=-s4
6728       if (.not. calc_grad) return
6729 C Derivatives in gamma(k-1)
6730       call matvec2(AECAderg(1,1,2),b1(1,itl1),auxvec(1))
6731       s3=0.5d0*scalar2(b1(1,itj1),auxvec(1))
6732       s4=-0.25d0*scalar2(vv(1),Ctobrder(1,k))
6733       g_corr6_loc(k-1)=g_corr6_loc(k-1)-ekont*(s3+s4)
6734 C Derivatives in gamma(l-1)
6735       call matvec2(AECAderg(1,1,1),b1(1,itk1),auxvec(1))
6736       s2=0.5d0*scalar2(b1(1,itk),auxvec(1))
6737       call matmat2(auxmat(1,1),AECAderg(1,1,1),pizda(1,1))
6738       vv(1)=pizda(1,1)+pizda(2,2)
6739       vv(2)=pizda(2,1)-pizda(1,2)
6740       s4=-0.25d0*scalar2(vv(1),Ctobr(1,k))
6741       g_corr6_loc(l-1)=g_corr6_loc(l-1)-ekont*(s2+s4) 
6742 C Cartesian derivatives.
6743       do iii=1,2
6744         do kkk=1,5
6745           do lll=1,3
6746 #ifdef MOMENT
6747             if (iii.eq.1) then
6748               s1=dipderx(lll,kkk,4,jj,i)*dip(4,kk,k)
6749             else
6750               s1=dip(4,jj,i)*dipderx(lll,kkk,4,kk,k)
6751             endif
6752 #endif
6753             call matvec2(AECAderx(1,1,lll,kkk,iii,1),b1(1,itk1),
6754      &        auxvec(1))
6755             s2=0.5d0*scalar2(b1(1,itk),auxvec(1))
6756             call matvec2(AECAderx(1,1,lll,kkk,iii,2),b1(1,itl1),
6757      &        auxvec(1))
6758             s3=0.5d0*scalar2(b1(1,itj1),auxvec(1))
6759             call matmat2(auxmat(1,1),AECAderx(1,1,lll,kkk,iii,1),
6760      &        pizda(1,1))
6761             vv(1)=pizda(1,1)+pizda(2,2)
6762             vv(2)=pizda(2,1)-pizda(1,2)
6763             s4=-0.25d0*scalar2(vv(1),Ctobr(1,k))
6764 #ifdef MOMENT
6765             derx(lll,kkk,iii)=derx(lll,kkk,iii)-(s1+s2+s4)
6766 #else
6767             derx(lll,kkk,iii)=derx(lll,kkk,iii)-(s2+s4)
6768 #endif
6769             if (swap) then
6770               derx(lll,kkk,3-iii)=derx(lll,kkk,3-iii)-s3
6771             else
6772               derx(lll,kkk,iii)=derx(lll,kkk,iii)-s3
6773             endif
6774 c            derx(lll,kkk,iii)=derx(lll,kkk,iii)-s4
6775           enddo
6776         enddo
6777       enddo
6778       return
6779       end
6780 c----------------------------------------------------------------------------
6781       double precision function eello6_graph4(i,j,k,l,jj,kk,imat,swap)
6782       implicit real*8 (a-h,o-z)
6783       include 'DIMENSIONS'
6784       include 'DIMENSIONS.ZSCOPT'
6785       include 'COMMON.IOUNITS'
6786       include 'COMMON.CHAIN'
6787       include 'COMMON.DERIV'
6788       include 'COMMON.INTERACT'
6789       include 'COMMON.CONTACTS'
6790       include 'COMMON.TORSION'
6791       include 'COMMON.VAR'
6792       include 'COMMON.GEO'
6793       include 'COMMON.FFIELD'
6794       double precision vv(2),pizda(2,2),auxmat(2,2),auxvec(2),
6795      & auxvec1(2),auxmat1(2,2)
6796       logical swap
6797 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
6798 C                                                                              C
6799 C      Parallel       Antiparallel                                             C
6800 C                                                                              C
6801 C          o             o                                                     C 
6802 C         /l\   /   \   /j\                                                    C
6803 C        /   \ /     \ /   \                                                   C
6804 C       /| o |o       o| o |\                                                  C
6805 C     \ j|/k\|      \  |/k\|l                                                  C
6806 C      \ /   \       \ /   \                                                   C
6807 C       o     \       o     \                                                  C
6808 C       i             i                                                        C
6809 C                                                                              C
6810 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
6811 C
6812 C 4/7/01 AL Component s1 was removed, because it pertains to the respective 
6813 C           energy moment and not to the cluster cumulant.
6814 cd      write (2,*) 'eello_graph4: wturn6',wturn6
6815       iti=itortyp(itype(i))
6816       itj=itortyp(itype(j))
6817       if (j.lt.nres-1) then
6818         itj1=itortyp(itype(j+1))
6819       else
6820         itj1=ntortyp+1
6821       endif
6822       itk=itortyp(itype(k))
6823       if (k.lt.nres-1) then
6824         itk1=itortyp(itype(k+1))
6825       else
6826         itk1=ntortyp+1
6827       endif
6828       itl=itortyp(itype(l))
6829       if (l.lt.nres-1) then
6830         itl1=itortyp(itype(l+1))
6831       else
6832         itl1=ntortyp+1
6833       endif
6834 cd      write (2,*) 'eello6_graph4:','i',i,' j',j,' k',k,' l',l
6835 cd      write (2,*) 'iti',iti,' itj',itj,' itj1',itj1,' itk',itk,
6836 cd     & ' itl',itl,' itl1',itl1
6837 #ifdef MOMENT
6838       if (imat.eq.1) then
6839         s1=dip(3,jj,i)*dip(3,kk,k)
6840       else
6841         s1=dip(2,jj,j)*dip(2,kk,l)
6842       endif
6843 #endif
6844       call matvec2(AECA(1,1,imat),Ub2(1,k),auxvec(1))
6845       s2=0.5d0*scalar2(Ub2(1,i),auxvec(1))
6846       if (j.eq.l+1) then
6847         call matvec2(ADtEA1(1,1,3-imat),b1(1,itj1),auxvec1(1))
6848         s3=-0.5d0*scalar2(b1(1,itj),auxvec1(1))
6849       else
6850         call matvec2(ADtEA1(1,1,3-imat),b1(1,itl1),auxvec1(1))
6851         s3=-0.5d0*scalar2(b1(1,itl),auxvec1(1))
6852       endif
6853       call transpose2(EUg(1,1,k),auxmat(1,1))
6854       call matmat2(AECA(1,1,imat),auxmat(1,1),pizda(1,1))
6855       vv(1)=pizda(1,1)-pizda(2,2)
6856       vv(2)=pizda(2,1)+pizda(1,2)
6857       s4=0.25d0*scalar2(vv(1),Dtobr2(1,i))
6858 cd      write (2,*) 'eello6_graph4:','s1',s1,' s2',s2,' s3',s3,' s4',s4
6859 #ifdef MOMENT
6860       eello6_graph4=-(s1+s2+s3+s4)
6861 #else
6862       eello6_graph4=-(s2+s3+s4)
6863 #endif
6864       if (.not. calc_grad) return
6865 C Derivatives in gamma(i-1)
6866       if (i.gt.1) then
6867 #ifdef MOMENT
6868         if (imat.eq.1) then
6869           s1=dipderg(2,jj,i)*dip(3,kk,k)
6870         else
6871           s1=dipderg(4,jj,j)*dip(2,kk,l)
6872         endif
6873 #endif
6874         s2=0.5d0*scalar2(Ub2der(1,i),auxvec(1))
6875         if (j.eq.l+1) then
6876           call matvec2(ADtEA1derg(1,1,1,3-imat),b1(1,itj1),auxvec1(1))
6877           s3=-0.5d0*scalar2(b1(1,itj),auxvec1(1))
6878         else
6879           call matvec2(ADtEA1derg(1,1,1,3-imat),b1(1,itl1),auxvec1(1))
6880           s3=-0.5d0*scalar2(b1(1,itl),auxvec1(1))
6881         endif
6882         s4=0.25d0*scalar2(vv(1),Dtobr2der(1,i))
6883         if (wturn6.gt.0.0d0 .and. k.eq.l+4 .and. i.eq.j+2) then
6884 cd          write (2,*) 'turn6 derivatives'
6885 #ifdef MOMENT
6886           gel_loc_turn6(i-1)=gel_loc_turn6(i-1)-ekont*(s1+s2+s3+s4)
6887 #else
6888           gel_loc_turn6(i-1)=gel_loc_turn6(i-1)-ekont*(s2+s3+s4)
6889 #endif
6890         else
6891 #ifdef MOMENT
6892           g_corr6_loc(i-1)=g_corr6_loc(i-1)-ekont*(s1+s2+s3+s4)
6893 #else
6894           g_corr6_loc(i-1)=g_corr6_loc(i-1)-ekont*(s2+s3+s4)
6895 #endif
6896         endif
6897       endif
6898 C Derivatives in gamma(k-1)
6899 #ifdef MOMENT
6900       if (imat.eq.1) then
6901         s1=dip(3,jj,i)*dipderg(2,kk,k)
6902       else
6903         s1=dip(2,jj,j)*dipderg(4,kk,l)
6904       endif
6905 #endif
6906       call matvec2(AECA(1,1,imat),Ub2der(1,k),auxvec1(1))
6907       s2=0.5d0*scalar2(Ub2(1,i),auxvec1(1))
6908       if (j.eq.l+1) then
6909         call matvec2(ADtEA1derg(1,1,2,3-imat),b1(1,itj1),auxvec1(1))
6910         s3=-0.5d0*scalar2(b1(1,itj),auxvec1(1))
6911       else
6912         call matvec2(ADtEA1derg(1,1,2,3-imat),b1(1,itl1),auxvec1(1))
6913         s3=-0.5d0*scalar2(b1(1,itl),auxvec1(1))
6914       endif
6915       call transpose2(EUgder(1,1,k),auxmat1(1,1))
6916       call matmat2(AECA(1,1,imat),auxmat1(1,1),pizda(1,1))
6917       vv(1)=pizda(1,1)-pizda(2,2)
6918       vv(2)=pizda(2,1)+pizda(1,2)
6919       s4=0.25d0*scalar2(vv(1),Dtobr2(1,i))
6920       if (wturn6.gt.0.0d0 .and. k.eq.l+4 .and. i.eq.j+2) then
6921 #ifdef MOMENT
6922         gel_loc_turn6(k-1)=gel_loc_turn6(k-1)-ekont*(s1+s2+s3+s4)
6923 #else
6924         gel_loc_turn6(k-1)=gel_loc_turn6(k-1)-ekont*(s2+s3+s4)
6925 #endif
6926       else
6927 #ifdef MOMENT
6928         g_corr6_loc(k-1)=g_corr6_loc(k-1)-ekont*(s1+s2+s3+s4)
6929 #else
6930         g_corr6_loc(k-1)=g_corr6_loc(k-1)-ekont*(s2+s3+s4)
6931 #endif
6932       endif
6933 C Derivatives in gamma(j-1) or gamma(l-1)
6934       if (l.eq.j+1 .and. l.gt.1) then
6935         call matvec2(AECAderg(1,1,imat),Ub2(1,k),auxvec(1))
6936         s2=0.5d0*scalar2(Ub2(1,i),auxvec(1))
6937         call matmat2(AECAderg(1,1,imat),auxmat(1,1),pizda(1,1))
6938         vv(1)=pizda(1,1)-pizda(2,2)
6939         vv(2)=pizda(2,1)+pizda(1,2)
6940         s4=0.25d0*scalar2(vv(1),Dtobr2(1,i))
6941         g_corr6_loc(l-1)=g_corr6_loc(l-1)-ekont*(s2+s4)
6942       else if (j.gt.1) then
6943         call matvec2(AECAderg(1,1,imat),Ub2(1,k),auxvec(1))
6944         s2=0.5d0*scalar2(Ub2(1,i),auxvec(1))
6945         call matmat2(AECAderg(1,1,imat),auxmat(1,1),pizda(1,1))
6946         vv(1)=pizda(1,1)-pizda(2,2)
6947         vv(2)=pizda(2,1)+pizda(1,2)
6948         s4=0.25d0*scalar2(vv(1),Dtobr2(1,i))
6949         if (wturn6.gt.0.0d0 .and. k.eq.l+4 .and. i.eq.j+2) then
6950           gel_loc_turn6(j-1)=gel_loc_turn6(j-1)-ekont*(s2+s4)
6951         else
6952           g_corr6_loc(j-1)=g_corr6_loc(j-1)-ekont*(s2+s4)
6953         endif
6954       endif
6955 C Cartesian derivatives.
6956       do iii=1,2
6957         do kkk=1,5
6958           do lll=1,3
6959 #ifdef MOMENT
6960             if (iii.eq.1) then
6961               if (imat.eq.1) then
6962                 s1=dipderx(lll,kkk,3,jj,i)*dip(3,kk,k)
6963               else
6964                 s1=dipderx(lll,kkk,2,jj,j)*dip(2,kk,l)
6965               endif
6966             else
6967               if (imat.eq.1) then
6968                 s1=dip(3,jj,i)*dipderx(lll,kkk,3,kk,k)
6969               else
6970                 s1=dip(2,jj,j)*dipderx(lll,kkk,2,kk,l)
6971               endif
6972             endif
6973 #endif
6974             call matvec2(AECAderx(1,1,lll,kkk,iii,imat),Ub2(1,k),
6975      &        auxvec(1))
6976             s2=0.5d0*scalar2(Ub2(1,i),auxvec(1))
6977             if (j.eq.l+1) then
6978               call matvec2(ADtEA1derx(1,1,lll,kkk,iii,3-imat),
6979      &          b1(1,itj1),auxvec(1))
6980               s3=-0.5d0*scalar2(b1(1,itj),auxvec(1))
6981             else
6982               call matvec2(ADtEA1derx(1,1,lll,kkk,iii,3-imat),
6983      &          b1(1,itl1),auxvec(1))
6984               s3=-0.5d0*scalar2(b1(1,itl),auxvec(1))
6985             endif
6986             call matmat2(AECAderx(1,1,lll,kkk,iii,imat),auxmat(1,1),
6987      &        pizda(1,1))
6988             vv(1)=pizda(1,1)-pizda(2,2)
6989             vv(2)=pizda(2,1)+pizda(1,2)
6990             s4=0.25d0*scalar2(vv(1),Dtobr2(1,i))
6991             if (swap) then
6992               if (wturn6.gt.0.0d0 .and. k.eq.l+4 .and. i.eq.j+2) then
6993 #ifdef MOMENT
6994                 derx_turn(lll,kkk,3-iii)=derx_turn(lll,kkk,3-iii)
6995      &             -(s1+s2+s4)
6996 #else
6997                 derx_turn(lll,kkk,3-iii)=derx_turn(lll,kkk,3-iii)
6998      &             -(s2+s4)
6999 #endif
7000                 derx_turn(lll,kkk,iii)=derx_turn(lll,kkk,iii)-s3
7001               else
7002 #ifdef MOMENT
7003                 derx(lll,kkk,3-iii)=derx(lll,kkk,3-iii)-(s1+s2+s4)
7004 #else
7005                 derx(lll,kkk,3-iii)=derx(lll,kkk,3-iii)-(s2+s4)
7006 #endif
7007                 derx(lll,kkk,iii)=derx(lll,kkk,iii)-s3
7008               endif
7009             else
7010 #ifdef MOMENT
7011               derx(lll,kkk,iii)=derx(lll,kkk,iii)-(s1+s2+s4)
7012 #else
7013               derx(lll,kkk,iii)=derx(lll,kkk,iii)-(s2+s4)
7014 #endif
7015               if (l.eq.j+1) then
7016                 derx(lll,kkk,iii)=derx(lll,kkk,iii)-s3
7017               else 
7018                 derx(lll,kkk,3-iii)=derx(lll,kkk,3-iii)-s3
7019               endif
7020             endif 
7021           enddo
7022         enddo
7023       enddo
7024       return
7025       end
7026 c----------------------------------------------------------------------------
7027       double precision function eello_turn6(i,jj,kk)
7028       implicit real*8 (a-h,o-z)
7029       include 'DIMENSIONS'
7030       include 'DIMENSIONS.ZSCOPT'
7031       include 'COMMON.IOUNITS'
7032       include 'COMMON.CHAIN'
7033       include 'COMMON.DERIV'
7034       include 'COMMON.INTERACT'
7035       include 'COMMON.CONTACTS'
7036       include 'COMMON.TORSION'
7037       include 'COMMON.VAR'
7038       include 'COMMON.GEO'
7039       double precision vtemp1(2),vtemp2(2),vtemp3(2),vtemp4(2),
7040      &  atemp(2,2),auxmat(2,2),achuj_temp(2,2),gtemp(2,2),gvec(2),
7041      &  ggg1(3),ggg2(3)
7042       double precision vtemp1d(2),vtemp2d(2),vtemp3d(2),vtemp4d(2),
7043      &  atempd(2,2),auxmatd(2,2),achuj_tempd(2,2),gtempd(2,2),gvecd(2)
7044 C 4/7/01 AL Components s1, s8, and s13 were removed, because they pertain to
7045 C           the respective energy moment and not to the cluster cumulant.
7046       eello_turn6=0.0d0
7047       j=i+4
7048       k=i+1
7049       l=i+3
7050       iti=itortyp(itype(i))
7051       itk=itortyp(itype(k))
7052       itk1=itortyp(itype(k+1))
7053       itl=itortyp(itype(l))
7054       itj=itortyp(itype(j))
7055 cd      write (2,*) 'itk',itk,' itk1',itk1,' itl',itl,' itj',itj
7056 cd      write (2,*) 'i',i,' k',k,' j',j,' l',l
7057 cd      if (i.ne.1 .or. j.ne.3 .or. k.ne.2 .or. l.ne.4) then
7058 cd        eello6=0.0d0
7059 cd        return
7060 cd      endif
7061 cd      write (iout,*)
7062 cd     &   'EELLO6: Contacts have occurred for peptide groups',i,j,
7063 cd     &   ' and',k,l
7064 cd      call checkint_turn6(i,jj,kk,eel_turn6_num)
7065       do iii=1,2
7066         do kkk=1,5
7067           do lll=1,3
7068             derx_turn(lll,kkk,iii)=0.0d0
7069           enddo
7070         enddo
7071       enddo
7072 cd      eij=1.0d0
7073 cd      ekl=1.0d0
7074 cd      ekont=1.0d0
7075       eello6_5=eello6_graph4(l,k,j,i,kk,jj,2,.true.)
7076 cd      eello6_5=0.0d0
7077 cd      write (2,*) 'eello6_5',eello6_5
7078 #ifdef MOMENT
7079       call transpose2(AEA(1,1,1),auxmat(1,1))
7080       call matmat2(EUg(1,1,i+1),auxmat(1,1),auxmat(1,1))
7081       ss1=scalar2(Ub2(1,i+2),b1(1,itl))
7082       s1 = (auxmat(1,1)+auxmat(2,2))*ss1
7083 #else
7084       s1 = 0.0d0
7085 #endif
7086       call matvec2(EUg(1,1,i+2),b1(1,itl),vtemp1(1))
7087       call matvec2(AEA(1,1,1),vtemp1(1),vtemp1(1))
7088       s2 = scalar2(b1(1,itk),vtemp1(1))
7089 #ifdef MOMENT
7090       call transpose2(AEA(1,1,2),atemp(1,1))
7091       call matmat2(atemp(1,1),EUg(1,1,i+4),atemp(1,1))
7092       call matvec2(Ug2(1,1,i+2),dd(1,1,itk1),vtemp2(1))
7093       s8 = -(atemp(1,1)+atemp(2,2))*scalar2(cc(1,1,itl),vtemp2(1))
7094 #else
7095       s8=0.0d0
7096 #endif
7097       call matmat2(EUg(1,1,i+3),AEA(1,1,2),auxmat(1,1))
7098       call matvec2(auxmat(1,1),Ub2(1,i+4),vtemp3(1))
7099       s12 = scalar2(Ub2(1,i+2),vtemp3(1))
7100 #ifdef MOMENT
7101       call transpose2(a_chuj(1,1,kk,i+1),achuj_temp(1,1))
7102       call matmat2(achuj_temp(1,1),EUg(1,1,i+2),gtemp(1,1))
7103       call matmat2(gtemp(1,1),EUg(1,1,i+3),gtemp(1,1)) 
7104       call matvec2(a_chuj(1,1,jj,i),Ub2(1,i+4),vtemp4(1)) 
7105       ss13 = scalar2(b1(1,itk),vtemp4(1))
7106       s13 = (gtemp(1,1)+gtemp(2,2))*ss13
7107 #else
7108       s13=0.0d0
7109 #endif
7110 c      write (2,*) 's1,s2,s8,s12,s13',s1,s2,s8,s12,s13
7111 c      s1=0.0d0
7112 c      s2=0.0d0
7113 c      s8=0.0d0
7114 c      s12=0.0d0
7115 c      s13=0.0d0
7116       eel_turn6 = eello6_5 - 0.5d0*(s1+s2+s12+s8+s13)
7117       if (calc_grad) then
7118 C Derivatives in gamma(i+2)
7119 #ifdef MOMENT
7120       call transpose2(AEA(1,1,1),auxmatd(1,1))
7121       call matmat2(EUgder(1,1,i+1),auxmatd(1,1),auxmatd(1,1))
7122       s1d = (auxmatd(1,1)+auxmatd(2,2))*ss1
7123       call transpose2(AEAderg(1,1,2),atempd(1,1))
7124       call matmat2(atempd(1,1),EUg(1,1,i+4),atempd(1,1))
7125       s8d = -(atempd(1,1)+atempd(2,2))*scalar2(cc(1,1,itl),vtemp2(1))
7126 #else
7127       s8d=0.0d0
7128 #endif
7129       call matmat2(EUg(1,1,i+3),AEAderg(1,1,2),auxmatd(1,1))
7130       call matvec2(auxmatd(1,1),Ub2(1,i+4),vtemp3d(1))
7131       s12d = scalar2(Ub2(1,i+2),vtemp3d(1))
7132 c      s1d=0.0d0
7133 c      s2d=0.0d0
7134 c      s8d=0.0d0
7135 c      s12d=0.0d0
7136 c      s13d=0.0d0
7137       gel_loc_turn6(i)=gel_loc_turn6(i)-0.5d0*ekont*(s1d+s8d+s12d)
7138 C Derivatives in gamma(i+3)
7139 #ifdef MOMENT
7140       call transpose2(AEA(1,1,1),auxmatd(1,1))
7141       call matmat2(EUg(1,1,i+1),auxmatd(1,1),auxmatd(1,1))
7142       ss1d=scalar2(Ub2der(1,i+2),b1(1,itl))
7143       s1d = (auxmatd(1,1)+auxmatd(2,2))*ss1d
7144 #else
7145       s1d=0.0d0
7146 #endif
7147       call matvec2(EUgder(1,1,i+2),b1(1,itl),vtemp1d(1))
7148       call matvec2(AEA(1,1,1),vtemp1d(1),vtemp1d(1))
7149       s2d = scalar2(b1(1,itk),vtemp1d(1))
7150 #ifdef MOMENT
7151       call matvec2(Ug2der(1,1,i+2),dd(1,1,itk1),vtemp2d(1))
7152       s8d = -(atemp(1,1)+atemp(2,2))*scalar2(cc(1,1,itl),vtemp2d(1))
7153 #endif
7154       s12d = scalar2(Ub2der(1,i+2),vtemp3(1))
7155 #ifdef MOMENT
7156       call matmat2(achuj_temp(1,1),EUgder(1,1,i+2),gtempd(1,1))
7157       call matmat2(gtempd(1,1),EUg(1,1,i+3),gtempd(1,1)) 
7158       s13d = (gtempd(1,1)+gtempd(2,2))*ss13
7159 #else
7160       s13d=0.0d0
7161 #endif
7162 c      s1d=0.0d0
7163 c      s2d=0.0d0
7164 c      s8d=0.0d0
7165 c      s12d=0.0d0
7166 c      s13d=0.0d0
7167 #ifdef MOMENT
7168       gel_loc_turn6(i+1)=gel_loc_turn6(i+1)
7169      &               -0.5d0*ekont*(s1d+s2d+s8d+s12d+s13d)
7170 #else
7171       gel_loc_turn6(i+1)=gel_loc_turn6(i+1)
7172      &               -0.5d0*ekont*(s2d+s12d)
7173 #endif
7174 C Derivatives in gamma(i+4)
7175       call matmat2(EUgder(1,1,i+3),AEA(1,1,2),auxmatd(1,1))
7176       call matvec2(auxmatd(1,1),Ub2(1,i+4),vtemp3d(1))
7177       s12d = scalar2(Ub2(1,i+2),vtemp3d(1))
7178 #ifdef MOMENT
7179       call matmat2(achuj_temp(1,1),EUg(1,1,i+2),gtempd(1,1))
7180       call matmat2(gtempd(1,1),EUgder(1,1,i+3),gtempd(1,1)) 
7181       s13d = (gtempd(1,1)+gtempd(2,2))*ss13
7182 #else
7183       s13d = 0.0d0
7184 #endif
7185 c      s1d=0.0d0
7186 c      s2d=0.0d0
7187 c      s8d=0.0d0
7188 C      s12d=0.0d0
7189 c      s13d=0.0d0
7190 #ifdef MOMENT
7191       gel_loc_turn6(i+2)=gel_loc_turn6(i+2)-0.5d0*ekont*(s12d+s13d)
7192 #else
7193       gel_loc_turn6(i+2)=gel_loc_turn6(i+2)-0.5d0*ekont*(s12d)
7194 #endif
7195 C Derivatives in gamma(i+5)
7196 #ifdef MOMENT
7197       call transpose2(AEAderg(1,1,1),auxmatd(1,1))
7198       call matmat2(EUg(1,1,i+1),auxmatd(1,1),auxmatd(1,1))
7199       s1d = (auxmatd(1,1)+auxmatd(2,2))*ss1
7200 #else
7201       s1d = 0.0d0
7202 #endif
7203       call matvec2(EUg(1,1,i+2),b1(1,itl),vtemp1d(1))
7204       call matvec2(AEAderg(1,1,1),vtemp1d(1),vtemp1d(1))
7205       s2d = scalar2(b1(1,itk),vtemp1d(1))
7206 #ifdef MOMENT
7207       call transpose2(AEA(1,1,2),atempd(1,1))
7208       call matmat2(atempd(1,1),EUgder(1,1,i+4),atempd(1,1))
7209       s8d = -(atempd(1,1)+atempd(2,2))*scalar2(cc(1,1,itl),vtemp2(1))
7210 #else
7211       s8d = 0.0d0
7212 #endif
7213       call matvec2(auxmat(1,1),Ub2der(1,i+4),vtemp3d(1))
7214       s12d = scalar2(Ub2(1,i+2),vtemp3d(1))
7215 #ifdef MOMENT
7216       call matvec2(a_chuj(1,1,jj,i),Ub2der(1,i+4),vtemp4d(1)) 
7217       ss13d = scalar2(b1(1,itk),vtemp4d(1))
7218       s13d = (gtemp(1,1)+gtemp(2,2))*ss13d
7219 #else
7220       s13d = 0.0d0
7221 #endif
7222 c      s1d=0.0d0
7223 c      s2d=0.0d0
7224 c      s8d=0.0d0
7225 c      s12d=0.0d0
7226 c      s13d=0.0d0
7227 #ifdef MOMENT
7228       gel_loc_turn6(i+3)=gel_loc_turn6(i+3)
7229      &               -0.5d0*ekont*(s1d+s2d+s8d+s12d+s13d)
7230 #else
7231       gel_loc_turn6(i+3)=gel_loc_turn6(i+3)
7232      &               -0.5d0*ekont*(s2d+s12d)
7233 #endif
7234 C Cartesian derivatives
7235       do iii=1,2
7236         do kkk=1,5
7237           do lll=1,3
7238 #ifdef MOMENT
7239             call transpose2(AEAderx(1,1,lll,kkk,iii,1),auxmatd(1,1))
7240             call matmat2(EUg(1,1,i+1),auxmatd(1,1),auxmatd(1,1))
7241             s1d = (auxmatd(1,1)+auxmatd(2,2))*ss1
7242 #else
7243             s1d = 0.0d0
7244 #endif
7245             call matvec2(EUg(1,1,i+2),b1(1,itl),vtemp1(1))
7246             call matvec2(AEAderx(1,1,lll,kkk,iii,1),vtemp1(1),
7247      &          vtemp1d(1))
7248             s2d = scalar2(b1(1,itk),vtemp1d(1))
7249 #ifdef MOMENT
7250             call transpose2(AEAderx(1,1,lll,kkk,iii,2),atempd(1,1))
7251             call matmat2(atempd(1,1),EUg(1,1,i+4),atempd(1,1))
7252             s8d = -(atempd(1,1)+atempd(2,2))*
7253      &           scalar2(cc(1,1,itl),vtemp2(1))
7254 #else
7255             s8d = 0.0d0
7256 #endif
7257             call matmat2(EUg(1,1,i+3),AEAderx(1,1,lll,kkk,iii,2),
7258      &           auxmatd(1,1))
7259             call matvec2(auxmatd(1,1),Ub2(1,i+4),vtemp3d(1))
7260             s12d = scalar2(Ub2(1,i+2),vtemp3d(1))
7261 c      s1d=0.0d0
7262 c      s2d=0.0d0
7263 c      s8d=0.0d0
7264 c      s12d=0.0d0
7265 c      s13d=0.0d0
7266 #ifdef MOMENT
7267             derx_turn(lll,kkk,iii) = derx_turn(lll,kkk,iii) 
7268      &        - 0.5d0*(s1d+s2d)
7269 #else
7270             derx_turn(lll,kkk,iii) = derx_turn(lll,kkk,iii) 
7271      &        - 0.5d0*s2d
7272 #endif
7273 #ifdef MOMENT
7274             derx_turn(lll,kkk,3-iii) = derx_turn(lll,kkk,3-iii) 
7275      &        - 0.5d0*(s8d+s12d)
7276 #else
7277             derx_turn(lll,kkk,3-iii) = derx_turn(lll,kkk,3-iii) 
7278      &        - 0.5d0*s12d
7279 #endif
7280           enddo
7281         enddo
7282       enddo
7283 #ifdef MOMENT
7284       do kkk=1,5
7285         do lll=1,3
7286           call transpose2(a_chuj_der(1,1,lll,kkk,kk,i+1),
7287      &      achuj_tempd(1,1))
7288           call matmat2(achuj_tempd(1,1),EUg(1,1,i+2),gtempd(1,1))
7289           call matmat2(gtempd(1,1),EUg(1,1,i+3),gtempd(1,1)) 
7290           s13d=(gtempd(1,1)+gtempd(2,2))*ss13
7291           derx_turn(lll,kkk,2) = derx_turn(lll,kkk,2)-0.5d0*s13d
7292           call matvec2(a_chuj_der(1,1,lll,kkk,jj,i),Ub2(1,i+4),
7293      &      vtemp4d(1)) 
7294           ss13d = scalar2(b1(1,itk),vtemp4d(1))
7295           s13d = (gtemp(1,1)+gtemp(2,2))*ss13d
7296           derx_turn(lll,kkk,1) = derx_turn(lll,kkk,1)-0.5d0*s13d
7297         enddo
7298       enddo
7299 #endif
7300 cd      write(iout,*) 'eel6_turn6',eel_turn6,' eel_turn6_num',
7301 cd     &  16*eel_turn6_num
7302 cd      goto 1112
7303       if (j.lt.nres-1) then
7304         j1=j+1
7305         j2=j-1
7306       else
7307         j1=j-1
7308         j2=j-2
7309       endif
7310       if (l.lt.nres-1) then
7311         l1=l+1
7312         l2=l-1
7313       else
7314         l1=l-1
7315         l2=l-2
7316       endif
7317       do ll=1,3
7318         ggg1(ll)=eel_turn6*g_contij(ll,1)
7319         ggg2(ll)=eel_turn6*g_contij(ll,2)
7320         ghalf=0.5d0*ggg1(ll)
7321 cd        ghalf=0.0d0
7322         gcorr6_turn(ll,i)=gcorr6_turn(ll,i)+ghalf
7323      &    +ekont*derx_turn(ll,2,1)
7324         gcorr6_turn(ll,i+1)=gcorr6_turn(ll,i+1)+ekont*derx_turn(ll,3,1)
7325         gcorr6_turn(ll,j)=gcorr6_turn(ll,j)+ghalf
7326      &    +ekont*derx_turn(ll,4,1)
7327         gcorr6_turn(ll,j1)=gcorr6_turn(ll,j1)+ekont*derx_turn(ll,5,1)
7328         ghalf=0.5d0*ggg2(ll)
7329 cd        ghalf=0.0d0
7330         gcorr6_turn(ll,k)=gcorr6_turn(ll,k)+ghalf
7331      &    +ekont*derx_turn(ll,2,2)
7332         gcorr6_turn(ll,k+1)=gcorr6_turn(ll,k+1)+ekont*derx_turn(ll,3,2)
7333         gcorr6_turn(ll,l)=gcorr6_turn(ll,l)+ghalf
7334      &    +ekont*derx_turn(ll,4,2)
7335         gcorr6_turn(ll,l1)=gcorr6_turn(ll,l1)+ekont*derx_turn(ll,5,2)
7336       enddo
7337 cd      goto 1112
7338       do m=i+1,j-1
7339         do ll=1,3
7340           gcorr6_turn(ll,m)=gcorr6_turn(ll,m)+ggg1(ll)
7341         enddo
7342       enddo
7343       do m=k+1,l-1
7344         do ll=1,3
7345           gcorr6_turn(ll,m)=gcorr6_turn(ll,m)+ggg2(ll)
7346         enddo
7347       enddo
7348 1112  continue
7349       do m=i+2,j2
7350         do ll=1,3
7351           gcorr6_turn(ll,m)=gcorr6_turn(ll,m)+ekont*derx_turn(ll,1,1)
7352         enddo
7353       enddo
7354       do m=k+2,l2
7355         do ll=1,3
7356           gcorr6_turn(ll,m)=gcorr6_turn(ll,m)+ekont*derx_turn(ll,1,2)
7357         enddo
7358       enddo 
7359 cd      do iii=1,nres-3
7360 cd        write (2,*) iii,g_corr6_loc(iii)
7361 cd      enddo
7362       endif
7363       eello_turn6=ekont*eel_turn6
7364 cd      write (2,*) 'ekont',ekont
7365 cd      write (2,*) 'eel_turn6',ekont*eel_turn6
7366       return
7367       end
7368 crc-------------------------------------------------
7369       SUBROUTINE MATVEC2(A1,V1,V2)
7370       implicit real*8 (a-h,o-z)
7371       include 'DIMENSIONS'
7372       DIMENSION A1(2,2),V1(2),V2(2)
7373 c      DO 1 I=1,2
7374 c        VI=0.0
7375 c        DO 3 K=1,2
7376 c    3     VI=VI+A1(I,K)*V1(K)
7377 c        Vaux(I)=VI
7378 c    1 CONTINUE
7379
7380       vaux1=a1(1,1)*v1(1)+a1(1,2)*v1(2)
7381       vaux2=a1(2,1)*v1(1)+a1(2,2)*v1(2)
7382
7383       v2(1)=vaux1
7384       v2(2)=vaux2
7385       END
7386 C---------------------------------------
7387       SUBROUTINE MATMAT2(A1,A2,A3)
7388       implicit real*8 (a-h,o-z)
7389       include 'DIMENSIONS'
7390       DIMENSION A1(2,2),A2(2,2),A3(2,2)
7391 c      DIMENSION AI3(2,2)
7392 c        DO  J=1,2
7393 c          A3IJ=0.0
7394 c          DO K=1,2
7395 c           A3IJ=A3IJ+A1(I,K)*A2(K,J)
7396 c          enddo
7397 c          A3(I,J)=A3IJ
7398 c       enddo
7399 c      enddo
7400
7401       ai3_11=a1(1,1)*a2(1,1)+a1(1,2)*a2(2,1)
7402       ai3_12=a1(1,1)*a2(1,2)+a1(1,2)*a2(2,2)
7403       ai3_21=a1(2,1)*a2(1,1)+a1(2,2)*a2(2,1)
7404       ai3_22=a1(2,1)*a2(1,2)+a1(2,2)*a2(2,2)
7405
7406       A3(1,1)=AI3_11
7407       A3(2,1)=AI3_21
7408       A3(1,2)=AI3_12
7409       A3(2,2)=AI3_22
7410       END
7411
7412 c-------------------------------------------------------------------------
7413       double precision function scalar2(u,v)
7414       implicit none
7415       double precision u(2),v(2)
7416       double precision sc
7417       integer i
7418       scalar2=u(1)*v(1)+u(2)*v(2)
7419       return
7420       end
7421
7422 C-----------------------------------------------------------------------------
7423
7424       subroutine transpose2(a,at)
7425       implicit none
7426       double precision a(2,2),at(2,2)
7427       at(1,1)=a(1,1)
7428       at(1,2)=a(2,1)
7429       at(2,1)=a(1,2)
7430       at(2,2)=a(2,2)
7431       return
7432       end
7433 c--------------------------------------------------------------------------
7434       subroutine transpose(n,a,at)
7435       implicit none
7436       integer n,i,j
7437       double precision a(n,n),at(n,n)
7438       do i=1,n
7439         do j=1,n
7440           at(j,i)=a(i,j)
7441         enddo
7442       enddo
7443       return
7444       end
7445 C---------------------------------------------------------------------------
7446       subroutine prodmat3(a1,a2,kk,transp,prod)
7447       implicit none
7448       integer i,j
7449       double precision a1(2,2),a2(2,2),a2t(2,2),kk(2,2),prod(2,2)
7450       logical transp
7451 crc      double precision auxmat(2,2),prod_(2,2)
7452
7453       if (transp) then
7454 crc        call transpose2(kk(1,1),auxmat(1,1))
7455 crc        call matmat2(a1(1,1),auxmat(1,1),auxmat(1,1))
7456 crc        call matmat2(auxmat(1,1),a2(1,1),prod_(1,1)) 
7457         
7458            prod(1,1)=(a1(1,1)*kk(1,1)+a1(1,2)*kk(1,2))*a2(1,1)
7459      & +(a1(1,1)*kk(2,1)+a1(1,2)*kk(2,2))*a2(2,1)
7460            prod(1,2)=(a1(1,1)*kk(1,1)+a1(1,2)*kk(1,2))*a2(1,2)
7461      & +(a1(1,1)*kk(2,1)+a1(1,2)*kk(2,2))*a2(2,2)
7462            prod(2,1)=(a1(2,1)*kk(1,1)+a1(2,2)*kk(1,2))*a2(1,1)
7463      & +(a1(2,1)*kk(2,1)+a1(2,2)*kk(2,2))*a2(2,1)
7464            prod(2,2)=(a1(2,1)*kk(1,1)+a1(2,2)*kk(1,2))*a2(1,2)
7465      & +(a1(2,1)*kk(2,1)+a1(2,2)*kk(2,2))*a2(2,2)
7466
7467       else
7468 crc        call matmat2(a1(1,1),kk(1,1),auxmat(1,1))
7469 crc        call matmat2(auxmat(1,1),a2(1,1),prod_(1,1))
7470
7471            prod(1,1)=(a1(1,1)*kk(1,1)+a1(1,2)*kk(2,1))*a2(1,1)
7472      &  +(a1(1,1)*kk(1,2)+a1(1,2)*kk(2,2))*a2(2,1)
7473            prod(1,2)=(a1(1,1)*kk(1,1)+a1(1,2)*kk(2,1))*a2(1,2)
7474      &  +(a1(1,1)*kk(1,2)+a1(1,2)*kk(2,2))*a2(2,2)
7475            prod(2,1)=(a1(2,1)*kk(1,1)+a1(2,2)*kk(2,1))*a2(1,1)
7476      &  +(a1(2,1)*kk(1,2)+a1(2,2)*kk(2,2))*a2(2,1)
7477            prod(2,2)=(a1(2,1)*kk(1,1)+a1(2,2)*kk(2,1))*a2(1,2)
7478      &  +(a1(2,1)*kk(1,2)+a1(2,2)*kk(2,2))*a2(2,2)
7479
7480       endif
7481 c      call transpose2(a2(1,1),a2t(1,1))
7482
7483 crc      print *,transp
7484 crc      print *,((prod_(i,j),i=1,2),j=1,2)
7485 crc      print *,((prod(i,j),i=1,2),j=1,2)
7486
7487       return
7488       end
7489 C-----------------------------------------------------------------------------
7490       double precision function scalar(u,v)
7491       implicit none
7492       double precision u(3),v(3)
7493       double precision sc
7494       integer i
7495       sc=0.0d0
7496       do i=1,3
7497         sc=sc+u(i)*v(i)
7498       enddo
7499       scalar=sc
7500       return
7501       end
7502