source/unres/src_MD-M/chainbuild.F

   1       subroutine chainbuild
   2 C
   3 C Build the virtual polypeptide chain. Side-chain centroids are moveable.
   4 C As of 2/17/95.
   5 C
   6       implicit real*8 (a-h,o-z)
   7       include 'DIMENSIONS'
   8       include 'COMMON.CHAIN'
   9       include 'COMMON.LOCAL'
  10       include 'COMMON.GEO'
  11       include 'COMMON.VAR'
  12       include 'COMMON.IOUNITS'
  13       include 'COMMON.NAMES'
  14       include 'COMMON.INTERACT'
  15       double precision e1(3),e2(3),e3(3)
  16       logical lprn,perbox,fail
  17 C Set lprn=.true. for debugging
  18       lprn = .false.
  19       perbox=.false.
  20       fail=.false.
  21       print *, 'enter chainbuild'
  22       if (perbox) then
  23       cost=dcos(theta(3))
  24       sint=dsin(theta(3))
  25       print *,'before refsys'
  26       call refsys(2,3,4,e1,e2,e3,fail)
  27       print *,'after refsys'
  28           if (fail) then
  29             e2(1)=0.0d0
  30             e2(2)=1.0d0
  31             e2(3)=0.0d0
  32           endif
  33       dc(1,0)=c(1,1)
  34       dc(2,0)=c(2,1)
  35       dc(3,0)=c(3,1)
  36       print *,'dc',dc(1,0),dc(2,0),dc(3,0)
  37       dc(1,1)=c(1,2)-c(1,1)
  38       dc(2,1)=c(2,2)-c(2,1)
  39       dc(3,1)=c(3,2)-c(3,1)
  40       dc(1,2)=c(1,3)-c(1,2)
  41       dc(2,2)=c(2,3)-c(2,2)
  42       dc(3,2)=c(3,3)-c(3,2)
  43       t(1,1,1)=e1(1)
  44       t(1,2,1)=e1(2)
  45       t(1,3,1)=e1(3)
  46       t(2,1,1)=e2(1)
  47       t(2,2,1)=e2(2)
  48       t(2,3,1)=e2(3)
  49       t(3,1,1)=e3(1)
  50       t(3,2,1)=e3(2)
  51       t(3,3,1)=e3(3)
  52       veclen=0.0d0
  53       do i=1,3
  54        veclen=veclen+(c(i,2)-c(i,1))**2
  55       enddo
  56       veclen=sqrt(veclen)
  57       r(1,1,1)= 1.0D0
  58       r(1,2,1)= 0.0D0
  59       r(1,3,1)= 0.0D0
  60       r(2,1,1)= 0.0D0
  61       r(2,2,1)= 1.0D0
  62       r(2,3,1)= 0.0D0
  63       r(3,1,1)= 0.0D0
  64       r(3,2,1)= 0.0D0
  65       r(3,3,1)= 1.0D0
  66       do i=1,3
  67         do j=1,3
  68           rt(i,j,1)=t(i,j,1)
  69         enddo
  70       enddo
  71       do i=1,3
  72         do j=1,3
  73           prod(i,j,1)=0.0D0
  74           prod(i,j,2)=t(i,j,1)
  75         enddo
  76         prod(i,i,1)=1.0D0
  77       enddo
  78         call locate_side_chain(2)
  79       do i=4,nres
  80 #ifdef OSF
  81       theti=theta(i)
  82       if (theti.ne.theti) theti=100.0
  83       phii=phi(i)
  84       if (phii.ne.phii) phii=180.0
  85 #else
  86       theti=theta(i)
  87       phii=phi(i)
  88 #endif
  89       cost=dcos(theti)
  90       sint=dsin(theti)
  91       cosphi=dcos(phii)
  92       sinphi=dsin(phii)
  93 * Define the matrices of the rotation about the virtual-bond valence angles
  94 * theta, T(i,j,k), virtual-bond dihedral angles gamma (miscalled PHI in this
  95 * program), R(i,j,k), and, the cumulative matrices of rotation RT
  96       t(1,1,i-2)=-cost
  97       t(1,2,i-2)=-sint
  98       t(1,3,i-2)= 0.0D0
  99       t(2,1,i-2)=-sint
 100       t(2,2,i-2)= cost
 101       t(2,3,i-2)= 0.0D0
 102       t(3,1,i-2)= 0.0D0
 103       t(3,2,i-2)= 0.0D0
 104       t(3,3,i-2)= 1.0D0
 105       r(1,1,i-2)= 1.0D0
 106       r(1,2,i-2)= 0.0D0
 107       r(1,3,i-2)= 0.0D0
 108       r(2,1,i-2)= 0.0D0
 109       r(2,2,i-2)=-cosphi
 110       r(2,3,i-2)= sinphi
 111       r(3,1,i-2)= 0.0D0
 112       r(3,2,i-2)= sinphi
 113       r(3,3,i-2)= cosphi
 114       rt(1,1,i-2)=-cost
 115       rt(1,2,i-2)=-sint
 116       rt(1,3,i-2)=0.0D0
 117       rt(2,1,i-2)=sint*cosphi
 118       rt(2,2,i-2)=-cost*cosphi
 119       rt(2,3,i-2)=sinphi
 120       rt(3,1,i-2)=-sint*sinphi
 121       rt(3,2,i-2)=cost*sinphi
 122       rt(3,3,i-2)=cosphi
 123         call matmult(prod(1,1,i-2),rt(1,1,i-2),prod(1,1,i-1))
 124       do j=1,3
 125         dc_norm(j,i-1)=prod(j,1,i-1)
 126         dc(j,i-1)=vbld(i)*prod(j,1,i-1)
 127       enddo
 128         call locate_side_chain(i-1)
 129        enddo
 130       else
 131 C
 132 C Define the origin and orientation of the coordinate system and locate the
 133 C first three CA's and SC(2).
 134 C
 135       call orig_frame
 136 *
 137 * Build the alpha-carbon chain.
 138 *
 139       do i=4,nres
 140         call locate_next_res(i)
 141       enddo
 142 C
 143 C First and last SC must coincide with the corresponding CA.
 144 C
 145       do j=1,3
 146         dc(j,nres+1)=0.0D0
 147         dc_norm(j,nres+1)=0.0D0
 148         dc(j,nres+nres)=0.0D0
 149         dc_norm(j,nres+nres)=0.0D0
 150         c(j,nres+1)=c(j,1)
 151         c(j,nres+nres)=c(j,nres)
 152       enddo
 153 *
 154 * Temporary diagnosis
 155 *
 156       if (lprn) then
 157
 158       call cartprint
 159       write (iout,'(/a)') 'Recalculated internal coordinates'
 160       do i=2,nres-1
 161         do j=1,3
 162           c(j,maxres2)=0.5D0*(c(j,i-1)+c(j,i+1))
 163         enddo
 164         be=0.0D0
 165         if (i.gt.3) be=rad2deg*beta(i-3,i-2,i-1,i)
 166         be1=rad2deg*beta(nres+i,i,maxres2,i+1)
 167         alfai=0.0D0
 168         if (i.gt.2) alfai=rad2deg*alpha(i-2,i-1,i)
 169         write (iout,1212) restyp(itype(i)),i,dist(i-1,i),
 170      &  alfai,be,dist(nres+i,i),rad2deg*alpha(nres+i,i,maxres2),be1
 171       enddo
 172  1212 format (a3,'(',i3,')',2(f10.5,2f10.2))
 173
 174       endif
 175       endif
 176       return
 177       end
 178 c-------------------------------------------------------------------------
 179       subroutine orig_frame
 180 C
 181 C Define the origin and orientation of the coordinate system and locate
 182 C the first three atoms.
 183 C
 184       implicit real*8 (a-h,o-z)
 185       include 'DIMENSIONS'
 186       include 'COMMON.CHAIN'
 187       include 'COMMON.LOCAL'
 188       include 'COMMON.GEO'
 189       include 'COMMON.VAR'
 190       cost=dcos(theta(3))
 191       sint=dsin(theta(3))
 192       t(1,1,1)=-cost
 193       t(1,2,1)=-sint
 194       t(1,3,1)= 0.0D0
 195       t(2,1,1)=-sint
 196       t(2,2,1)= cost
 197       t(2,3,1)= 0.0D0
 198       t(3,1,1)= 0.0D0
 199       t(3,2,1)= 0.0D0
 200       t(3,3,1)= 1.0D0
 201       r(1,1,1)= 1.0D0
 202       r(1,2,1)= 0.0D0
 203       r(1,3,1)= 0.0D0
 204       r(2,1,1)= 0.0D0
 205       r(2,2,1)= 1.0D0
 206       r(2,3,1)= 0.0D0
 207       r(3,1,1)= 0.0D0
 208       r(3,2,1)= 0.0D0
 209       r(3,3,1)= 1.0D0
 210       do i=1,3
 211         do j=1,3
 212           rt(i,j,1)=t(i,j,1)
 213         enddo
 214       enddo
 215       do i=1,3
 216         do j=1,3
 217           prod(i,j,1)=0.0D0
 218           prod(i,j,2)=t(i,j,1)
 219         enddo
 220         prod(i,i,1)=1.0D0
 221       enddo
 222       c(1,1)=0.0D0
 223       c(2,1)=0.0D0
 224       c(3,1)=0.0D0
 225       c(1,2)=vbld(2)
 226       c(2,2)=0.0D0
 227       c(3,2)=0.0D0
 228       dc(1,0)=0.0d0
 229       dc(2,0)=0.0D0
 230       dc(3,0)=0.0D0
 231       dc(1,1)=vbld(2)
 232       dc(2,1)=0.0D0
 233       dc(3,1)=0.0D0
 234       dc_norm(1,0)=0.0D0
 235       dc_norm(2,0)=0.0D0
 236       dc_norm(3,0)=0.0D0
 237       dc_norm(1,1)=1.0D0
 238       dc_norm(2,1)=0.0D0
 239       dc_norm(3,1)=0.0D0
 240       do j=1,3
 241         dc_norm(j,2)=prod(j,1,2)
 242         dc(j,2)=vbld(3)*prod(j,1,2)
 243         c(j,3)=c(j,2)+dc(j,2)
 244       enddo
 245       call locate_side_chain(2)
 246       return
 247       end
 248 c-----------------------------------------------------------------------------
 249       subroutine locate_next_res(i)
 250 C
 251 C Locate CA(i) and SC(i-1)
 252 C
 253       implicit real*8 (a-h,o-z)
 254       include 'DIMENSIONS'
 255       include 'COMMON.CHAIN'
 256       include 'COMMON.LOCAL'
 257       include 'COMMON.GEO'
 258       include 'COMMON.VAR'
 259       include 'COMMON.IOUNITS'
 260       include 'COMMON.NAMES'
 261       include 'COMMON.INTERACT'
 262 C
 263 C Define the rotation matrices corresponding to CA(i)
 264 C
 265 #ifdef OSF
 266       theti=theta(i)
 267       if (theti.ne.theti) theti=100.0
 268       phii=phi(i)
 269       if (phii.ne.phii) phii=180.0
 270 #else
 271       theti=theta(i)
 272       phii=phi(i)
 273 #endif
 274       cost=dcos(theti)
 275       sint=dsin(theti)
 276       cosphi=dcos(phii)
 277       sinphi=dsin(phii)
 278 * Define the matrices of the rotation about the virtual-bond valence angles
 279 * theta, T(i,j,k), virtual-bond dihedral angles gamma (miscalled PHI in this
 280 * program), R(i,j,k), and, the cumulative matrices of rotation RT
 281       t(1,1,i-2)=-cost
 282       t(1,2,i-2)=-sint
 283       t(1,3,i-2)= 0.0D0
 284       t(2,1,i-2)=-sint
 285       t(2,2,i-2)= cost
 286       t(2,3,i-2)= 0.0D0
 287       t(3,1,i-2)= 0.0D0
 288       t(3,2,i-2)= 0.0D0
 289       t(3,3,i-2)= 1.0D0
 290       r(1,1,i-2)= 1.0D0
 291       r(1,2,i-2)= 0.0D0
 292       r(1,3,i-2)= 0.0D0
 293       r(2,1,i-2)= 0.0D0
 294       r(2,2,i-2)=-cosphi
 295       r(2,3,i-2)= sinphi
 296       r(3,1,i-2)= 0.0D0
 297       r(3,2,i-2)= sinphi
 298       r(3,3,i-2)= cosphi
 299       rt(1,1,i-2)=-cost
 300       rt(1,2,i-2)=-sint
 301       rt(1,3,i-2)=0.0D0
 302       rt(2,1,i-2)=sint*cosphi
 303       rt(2,2,i-2)=-cost*cosphi
 304       rt(2,3,i-2)=sinphi
 305       rt(3,1,i-2)=-sint*sinphi
 306       rt(3,2,i-2)=cost*sinphi
 307       rt(3,3,i-2)=cosphi
 308       call matmult(prod(1,1,i-2),rt(1,1,i-2),prod(1,1,i-1))
 309       do j=1,3
 310         dc_norm(j,i-1)=prod(j,1,i-1)
 311         dc(j,i-1)=vbld(i)*prod(j,1,i-1)
 312         c(j,i)=c(j,i-1)+dc(j,i-1)
 313       enddo
 314 cd    print '(2i3,2(3f10.5,5x))', i-1,i,(dc(j,i-1),j=1,3),(c(j,i),j=1,3)
 315 C
 316 C Now calculate the coordinates of SC(i-1)
 317 C
 318       call locate_side_chain(i-1)
 319       return
 320       end
 321 c-----------------------------------------------------------------------------
 322       subroutine locate_side_chain(i)
 323 C
 324 C Locate the side-chain centroid i, 1 < i < NRES. Put in C(*,NRES+i).
 325 C
 326       implicit real*8 (a-h,o-z)
 327       include 'DIMENSIONS'
 328       include 'COMMON.CHAIN'
 329       include 'COMMON.LOCAL'
 330       include 'COMMON.GEO'
 331       include 'COMMON.VAR'
 332       include 'COMMON.IOUNITS'
 333       include 'COMMON.NAMES'
 334       include 'COMMON.INTERACT'
 335       dimension xx(3)
 336
 337 c      dsci=dsc(itype(i))
 338 c      dsci_inv=dsc_inv(itype(i))
 339       dsci=vbld(i+nres)
 340       dsci_inv=vbld_inv(i+nres)
 341 #ifdef OSF
 342       alphi=alph(i)
 343       omegi=omeg(i)
 344       if (alphi.ne.alphi) alphi=100.0
 345       if (omegi.ne.omegi) omegi=-100.0
 346 #else
 347       alphi=alph(i)
 348       omegi=omeg(i)
 349 #endif
 350       cosalphi=dcos(alphi)
 351       sinalphi=dsin(alphi)
 352       cosomegi=dcos(omegi)
 353       sinomegi=dsin(omegi)
 354       xp= dsci*cosalphi
 355       yp= dsci*sinalphi*cosomegi
 356       zp=-dsci*sinalphi*sinomegi
 357 * Now we have to rotate the coordinate system by 180-theta(i)/2 so as to get its
 358 * X-axis aligned with the vector DC(*,i)
 359       theta2=pi-0.5D0*theta(i+1)
 360       cost2=dcos(theta2)
 361       sint2=dsin(theta2)
 362       xx(1)= xp*cost2+yp*sint2
 363       xx(2)=-xp*sint2+yp*cost2
 364       xx(3)= zp
 365 cd    print '(a3,i3,3f10.5,5x,3f10.5)',restyp(itype(i)),i,
 366 cd   &   xp,yp,zp,(xx(k),k=1,3)
 367       do j=1,3
 368         xloc(j,i)=xx(j)
 369       enddo
 370 * Bring the SC vectors to the common coordinate system.
 371       xx(1)=xloc(1,i)
 372       xx(2)=xloc(2,i)*r(2,2,i-1)+xloc(3,i)*r(2,3,i-1)
 373       xx(3)=xloc(2,i)*r(3,2,i-1)+xloc(3,i)*r(3,3,i-1)
 374       do j=1,3
 375         xrot(j,i)=xx(j)
 376       enddo
 377       do j=1,3
 378         rj=0.0D0
 379         do k=1,3
 380           rj=rj+prod(j,k,i-1)*xx(k)
 381         enddo
 382         dc(j,nres+i)=rj
 383         dc_norm(j,nres+i)=rj*dsci_inv
 384         c(j,nres+i)=c(j,i)+rj
 385       enddo
 386       return
 387       end
 388 c------------------------------------------
 389       subroutine returnbox
 390       include 'DIMENSIONS'
 391 #ifdef MPI
 392       include 'mpif.h'
 393 #endif
 394       include 'COMMON.CONTROL'
 395       include 'COMMON.VAR'
 396       include 'COMMON.MD'
 397 #ifndef LANG0
 398       include 'COMMON.LANGEVIN'
 399 #else
 400       include 'COMMON.LANGEVIN.lang0'
 401 #endif
 402       include 'COMMON.CHAIN'
 403       include 'COMMON.DERIV'
 404       include 'COMMON.GEO'
 405       include 'COMMON.LOCAL'
 406       include 'COMMON.INTERACT'
 407       include 'COMMON.IOUNITS'
 408       include 'COMMON.NAMES'
 409       include 'COMMON.TIME1'
 410       include 'COMMON.REMD'
 411       include 'COMMON.SETUP'
 412       include 'COMMON.MUCA'
 413       include 'COMMON.HAIRPIN'
 414         j=1
 415         chain_beg=1
 416 C        do i=1,nres
 417 C       write(*,*) 'initial', i,j,c(j,i)
 418 C        enddo
 419         do i=1,nres-1
 420          if ((itype(i).eq.ntyp1).and.(itype(i+1).eq.ntyp1)) then
 421           chain_end=i
 422           if (allareout.eq.1) then
 423             ireturnval=int(c(j,i)/boxxsize)
 424             if (c(j,i).le.0) ireturnval=ireturnval-1
 425             do k=chain_beg,chain_end
 426               c(j,k)=c(j,k)-ireturnval*boxxsize
 427               c(j,k+nres)=c(j,k+nres)-ireturnval*boxxsize
 428             enddo
 429            endif
 430            chain_beg=i+1
 431            allareout=1
 432          else
 433           if (int(c(j,i)/boxxsize).eq.0) allareout=0
 434          endif
 435         enddo
 436          if (allareout.eq.1) then
 437             ireturnval=int(c(j,i)/boxxsize)
 438             if (c(j,i).le.0) ireturnval=ireturnval-1
 439             do k=chain_beg,nres
 440               c(j,k)=c(j,k)-ireturnval*boxxsize
 441               c(j,k+nres)=c(j,k+nres)-ireturnval*boxxsize
 442             enddo
 443           endif
 444 C NO JUMP
 445 C        do i=1,nres
 446 C        write(*,*) 'befor no jump', i,j,c(j,i)
 447 C        enddo
 448         nojumpval=0
 449         do i=2,nres
 450            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 451              difference=abs(c(j,i-1)-c(j,i))
 452 C             print *,'diff', difference
 453              if (difference.gt.boxxsize/2.0) then
 454                 if (c(j,i-1).gt.c(j,i)) then
 455                   nojumpval=1
 456                  else
 457                    nojumpval=-1
 458                  endif
 459               else
 460               nojumpval=0
 461               endif
 462               endif
 463               c(j,i)=c(j,i)+nojumpval*boxxsize
 464               c(j,i+nres)=c(j,i+nres)+nojumpval*boxxsize
 465          enddo
 466        nojumpval=0
 467         do i=2,nres
 468            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 469              difference=abs(c(j,i-1)-c(j,i))
 470              if (difference.gt.boxxsize/2.0) then
 471                 if (c(j,i-1).gt.c(j,i)) then
 472                   nojumpval=1
 473                  else
 474                    nojumpval=-1
 475                  endif
 476               else
 477               nojumpval=0
 478               endif
 479              endif
 480               c(j,i)=c(j,i)+nojumpval*boxxsize
 481               c(j,i+nres)=c(j,i+nres)+nojumpval*boxxsize
 482          enddo
 483
 484 C        do i=1,nres
 485 C        write(*,*) 'after no jump', i,j,c(j,i)
 486 C        enddo
 487
 488 C NOW Y dimension
 489         j=2
 490         chain_beg=1
 491         do i=1,nres-1
 492          if ((itype(i).eq.ntyp1).and.(itype(i+1).eq.ntyp1)) then
 493           chain_end=i
 494           if (allareout.eq.1) then
 495             ireturnval=int(c(j,i)/boxysize)
 496             if (c(j,i).le.0) ireturnval=ireturnval-1
 497             do k=chain_beg,chain_end
 498               c(j,k)=c(j,k)-ireturnval*boxysize
 499              c(j,k+nres)=c(j,k+nres)-ireturnval*boxysize
 500             enddo
 501            endif
 502            chain_beg=i+1
 503            allareout=1
 504          else
 505           if (int(c(j,i)/boxysize).eq.0) allareout=0
 506          endif
 507         enddo
 508          if (allareout.eq.1) then
 509             ireturnval=int(c(j,i)/boxysize)
 510             if (c(j,i).le.0) ireturnval=ireturnval-1
 511             do k=chain_beg,nres
 512               c(j,k)=c(j,k)-ireturnval*boxysize
 513               c(j,k+nres)=c(j,k+nres)-ireturnval*boxysize
 514             enddo
 515           endif
 516         nojumpval=0
 517         do i=2,nres
 518            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 519              difference=abs(c(j,i-1)-c(j,i))
 520              if (difference.gt.boxysize/2.0) then
 521                 if (c(j,i-1).gt.c(j,i)) then
 522                   nojumpval=1
 523                  else
 524                    nojumpval=-1
 525                  endif
 526              else
 527               nojumpval=0
 528               endif
 529            endif
 530               c(j,i)=c(j,i)+nojumpval*boxysize
 531               c(j,i+nres)=c(j,i+nres)+nojumpval*boxysize
 532          enddo
 533       nojumpval=0
 534         do i=2,nres
 535            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 536              difference=abs(c(j,i-1)-c(j,i))
 537              if (difference.gt.boxysize/2.0) then
 538                 if (c(j,i-1).gt.c(j,i)) then
 539                   nojumpval=1
 540                  else
 541                    nojumpval=-1
 542                  endif
 543               else
 544               nojumpval=0
 545               endif
 546             endif
 547               c(j,i)=c(j,i)+nojumpval*boxysize
 548               c(j,i+nres)=c(j,i+nres)+nojumpval*boxysize
 549          enddo
 550        j=3
 551         chain_beg=1
 552         do i=1,nres-1
 553          if ((itype(i).eq.ntyp1).and.(itype(i+1).eq.ntyp1)) then
 554           chain_end=i
 555           if (allareout.eq.1) then
 556             ireturnval=int(c(j,i)/boxysize)
 557             if (c(j,i).le.0) ireturnval=ireturnval-1
 558             do k=chain_beg,chain_end
 559               c(j,k)=c(j,k)-ireturnval*boxzsize
 560               c(j,k+nres)=c(j,k+nres)-ireturnval*boxzsize
 561             enddo
 562            endif
 563            chain_beg=i+1
 564            allareout=1
 565          else
 566           if (int(c(j,i)/boxzsize).eq.0) allareout=0
 567          endif
 568         enddo
 569          if (allareout.eq.1) then
 570             ireturnval=int(c(j,i)/boxzsize)
 571             if (c(j,i).le.0) ireturnval=ireturnval-1
 572             do k=chain_beg,nres
 573               c(j,k)=c(j,k)-ireturnval*boxzsize
 574               c(j,k+nres)=c(j,k+nres)-ireturnval*boxzsize
 575             enddo
 576           endif
 577         nojumpval=0
 578         do i=2,nres
 579            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 580              difference=abs(c(j,i-1)-c(j,i))
 581              if (difference.gt.(boxzsize/2.0)) then
 582                 if (c(j,i-1).gt.c(j,i)) then
 583                   nojumpval=1
 584                  else
 585                    nojumpval=-1
 586                  endif
 587               else
 588               nojumpval=0
 589               endif
 590             endif
 591               c(j,i)=c(j,i)+nojumpval*boxzsize
 592               c(j,i+nres)=c(j,i+nres)+nojumpval*boxzsize
 593          enddo
 594        nojumpval=0
 595         do i=2,nres
 596            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 597              difference=abs(c(j,i-1)-c(j,i))
 598              if (difference.gt.boxzsize/2.0) then
 599                 if (c(j,i-1).gt.c(j,i)) then
 600                   nojumpval=1
 601                  else
 602                    nojumpval=-1
 603                  endif
 604               else
 605               nojumpval=0
 606               endif
 607             endif
 608              c(j,i)=c(j,i)+nojumpval*boxzsize
 609               c(j,i+nres)=c(j,i+nres)+nojumpval*boxzsize
 610          enddo
 611
 612         return
 613         end
 614