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