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       call chainbuild_cart
  23       return
  24       end
  25 #ifdef DEBUG
  26       if (perbox) then
  27       cost=dcos(theta(3))
  28       sint=dsin(theta(3))
  29       print *,'before refsys'
  30       call refsys(2,3,4,e1,e2,e3,fail)
  31       print *,'after refsys'
  32           if (fail) then
  33             e2(1)=0.0d0
  34             e2(2)=1.0d0
  35             e2(3)=0.0d0
  36           endif
  37       dc(1,0)=c(1,1)
  38       dc(2,0)=c(2,1)
  39       dc(3,0)=c(3,1)
  40       print *,'dc',dc(1,0),dc(2,0),dc(3,0)
  41       dc(1,1)=c(1,2)-c(1,1)
  42       dc(2,1)=c(2,2)-c(2,1)
  43       dc(3,1)=c(3,2)-c(3,1)
  44       dc(1,2)=c(1,3)-c(1,2)
  45       dc(2,2)=c(2,3)-c(2,2)
  46       dc(3,2)=c(3,3)-c(3,2)
  47       t(1,1,1)=e1(1)
  48       t(1,2,1)=e1(2)
  49       t(1,3,1)=e1(3)
  50       t(2,1,1)=e2(1)
  51       t(2,2,1)=e2(2)
  52       t(2,3,1)=e2(3)
  53       t(3,1,1)=e3(1)
  54       t(3,2,1)=e3(2)
  55       t(3,3,1)=e3(3)
  56       veclen=0.0d0
  57       do i=1,3
  58        veclen=veclen+(c(i,2)-c(i,1))**2
  59       enddo
  60       veclen=sqrt(veclen)
  61       r(1,1,1)= 1.0D0
  62       r(1,2,1)= 0.0D0
  63       r(1,3,1)= 0.0D0
  64       r(2,1,1)= 0.0D0
  65       r(2,2,1)= 1.0D0
  66       r(2,3,1)= 0.0D0
  67       r(3,1,1)= 0.0D0
  68       r(3,2,1)= 0.0D0
  69       r(3,3,1)= 1.0D0
  70       do i=1,3
  71         do j=1,3
  72           rt(i,j,1)=t(i,j,1)
  73         enddo
  74       enddo
  75       do i=1,3
  76         do j=1,3
  77           prod(i,j,1)=0.0D0
  78           prod(i,j,2)=t(i,j,1)
  79         enddo
  80         prod(i,i,1)=1.0D0
  81       enddo
  82         call locate_side_chain(2)
  83       do i=4,nres
  84 #ifdef OSF
  85       theti=theta(i)
  86       if (theti.ne.theti) theti=100.0
  87       phii=phi(i)
  88       if (phii.ne.phii) phii=180.0
  89 #else
  90       theti=theta(i)
  91       phii=phi(i)
  92 #endif
  93       cost=dcos(theti)
  94       sint=dsin(theti)
  95       cosphi=dcos(phii)
  96       sinphi=dsin(phii)
  97 * Define the matrices of the rotation about the virtual-bond valence angles
  98 * theta, T(i,j,k), virtual-bond dihedral angles gamma (miscalled PHI in this
  99 * program), R(i,j,k), and, the cumulative matrices of rotation RT
 100       t(1,1,i-2)=-cost
 101       t(1,2,i-2)=-sint
 102       t(1,3,i-2)= 0.0D0
 103       t(2,1,i-2)=-sint
 104       t(2,2,i-2)= cost
 105       t(2,3,i-2)= 0.0D0
 106       t(3,1,i-2)= 0.0D0
 107       t(3,2,i-2)= 0.0D0
 108       t(3,3,i-2)= 1.0D0
 109       r(1,1,i-2)= 1.0D0
 110       r(1,2,i-2)= 0.0D0
 111       r(1,3,i-2)= 0.0D0
 112       r(2,1,i-2)= 0.0D0
 113       r(2,2,i-2)=-cosphi
 114       r(2,3,i-2)= sinphi
 115       r(3,1,i-2)= 0.0D0
 116       r(3,2,i-2)= sinphi
 117       r(3,3,i-2)= cosphi
 118       rt(1,1,i-2)=-cost
 119       rt(1,2,i-2)=-sint
 120       rt(1,3,i-2)=0.0D0
 121       rt(2,1,i-2)=sint*cosphi
 122       rt(2,2,i-2)=-cost*cosphi
 123       rt(2,3,i-2)=sinphi
 124       rt(3,1,i-2)=-sint*sinphi
 125       rt(3,2,i-2)=cost*sinphi
 126       rt(3,3,i-2)=cosphi
 127         call matmult(prod(1,1,i-2),rt(1,1,i-2),prod(1,1,i-1))
 128       do j=1,3
 129         dc_norm(j,i-1)=prod(j,1,i-1)
 130         dc(j,i-1)=vbld(i)*prod(j,1,i-1)
 131       enddo
 132         call locate_side_chain(i-1)
 133        enddo
 134       else
 135 C
 136 C Define the origin and orientation of the coordinate system and locate the
 137 C first three CA's and SC(2).
 138 C
 139       call orig_frame
 140 *
 141 * Build the alpha-carbon chain.
 142 *
 143       do i=4,nres
 144         call locate_next_res(i)
 145       enddo
 146 C
 147 C First and last SC must coincide with the corresponding CA.
 148 C
 149       do j=1,3
 150         dc(j,nres+1)=0.0D0
 151         dc_norm(j,nres+1)=0.0D0
 152         dc(j,nres+nres)=0.0D0
 153         dc_norm(j,nres+nres)=0.0D0
 154         c(j,nres+1)=c(j,1)
 155         c(j,nres+nres)=c(j,nres)
 156       enddo
 157 *
 158 * Temporary diagnosis
 159 *
 160       if (lprn) then
 161
 162       call cartprint
 163       write (iout,'(/a)') 'Recalculated internal coordinates'
 164       do i=2,nres-1
 165         do j=1,3
 166           c(j,maxres2)=0.5D0*(c(j,i-1)+c(j,i+1))
 167         enddo
 168         be=0.0D0
 169         if (i.gt.3) be=rad2deg*beta(i-3,i-2,i-1,i)
 170         be1=rad2deg*beta(nres+i,i,maxres2,i+1)
 171         alfai=0.0D0
 172         if (i.gt.2) alfai=rad2deg*alpha(i-2,i-1,i)
 173         write (iout,1212) restyp(itype(i)),i,dist(i-1,i),
 174      &  alfai,be,dist(nres+i,i),rad2deg*alpha(nres+i,i,maxres2),be1
 175       enddo
 176  1212 format (a3,'(',i3,')',2(f10.5,2f10.2))
 177
 178       endif
 179       endif
 180       return
 181       end
 182 #endif
 183 c-------------------------------------------------------------------------
 184       subroutine orig_frame
 185 C
 186 C Define the origin and orientation of the coordinate system and locate
 187 C the first three atoms.
 188 C
 189       implicit real*8 (a-h,o-z)
 190       include 'DIMENSIONS'
 191       include 'COMMON.CHAIN'
 192       include 'COMMON.LOCAL'
 193       include 'COMMON.GEO'
 194       include 'COMMON.VAR'
 195       cost=dcos(theta(3))
 196       sint=dsin(theta(3))
 197       t(1,1,1)=-cost
 198       t(1,2,1)=-sint
 199       t(1,3,1)= 0.0D0
 200       t(2,1,1)=-sint
 201       t(2,2,1)= cost
 202       t(2,3,1)= 0.0D0
 203       t(3,1,1)= 0.0D0
 204       t(3,2,1)= 0.0D0
 205       t(3,3,1)= 1.0D0
 206       r(1,1,1)= 1.0D0
 207       r(1,2,1)= 0.0D0
 208       r(1,3,1)= 0.0D0
 209       r(2,1,1)= 0.0D0
 210       r(2,2,1)= 1.0D0
 211       r(2,3,1)= 0.0D0
 212       r(3,1,1)= 0.0D0
 213       r(3,2,1)= 0.0D0
 214       r(3,3,1)= 1.0D0
 215       do i=1,3
 216         do j=1,3
 217           rt(i,j,1)=t(i,j,1)
 218         enddo
 219       enddo
 220       do i=1,3
 221         do j=1,3
 222           prod(i,j,1)=0.0D0
 223           prod(i,j,2)=t(i,j,1)
 224         enddo
 225         prod(i,i,1)=1.0D0
 226       enddo
 227       c(1,1)=0.0D0
 228       c(2,1)=0.0D0
 229       c(3,1)=0.0D0
 230       c(1,2)=vbld(2)
 231       c(2,2)=0.0D0
 232       c(3,2)=0.0D0
 233       dc(1,0)=0.0d0
 234       dc(2,0)=0.0D0
 235       dc(3,0)=0.0D0
 236       dc(1,1)=vbld(2)
 237       dc(2,1)=0.0D0
 238       dc(3,1)=0.0D0
 239       dc_norm(1,0)=0.0D0
 240       dc_norm(2,0)=0.0D0
 241       dc_norm(3,0)=0.0D0
 242       dc_norm(1,1)=1.0D0
 243       dc_norm(2,1)=0.0D0
 244       dc_norm(3,1)=0.0D0
 245       do j=1,3
 246         dc_norm(j,2)=prod(j,1,2)
 247         dc(j,2)=vbld(3)*prod(j,1,2)
 248         c(j,3)=c(j,2)+dc(j,2)
 249       enddo
 250       call locate_side_chain(2)
 251       return
 252       end
 253 c-----------------------------------------------------------------------------
 254       subroutine locate_next_res(i)
 255 C
 256 C Locate CA(i) and SC(i-1)
 257 C
 258       implicit real*8 (a-h,o-z)
 259       include 'DIMENSIONS'
 260       include 'COMMON.CHAIN'
 261       include 'COMMON.LOCAL'
 262       include 'COMMON.GEO'
 263       include 'COMMON.VAR'
 264       include 'COMMON.IOUNITS'
 265       include 'COMMON.NAMES'
 266       include 'COMMON.INTERACT'
 267 C
 268 C Define the rotation matrices corresponding to CA(i)
 269 C
 270 #ifdef OSF
 271       theti=theta(i)
 272       if (theti.ne.theti) theti=100.0
 273       phii=phi(i)
 274       if (phii.ne.phii) phii=180.0
 275 #else
 276       theti=theta(i)
 277       phii=phi(i)
 278 #endif
 279       cost=dcos(theti)
 280       sint=dsin(theti)
 281       cosphi=dcos(phii)
 282       sinphi=dsin(phii)
 283 * Define the matrices of the rotation about the virtual-bond valence angles
 284 * theta, T(i,j,k), virtual-bond dihedral angles gamma (miscalled PHI in this
 285 * program), R(i,j,k), and, the cumulative matrices of rotation RT
 286       t(1,1,i-2)=-cost
 287       t(1,2,i-2)=-sint
 288       t(1,3,i-2)= 0.0D0
 289       t(2,1,i-2)=-sint
 290       t(2,2,i-2)= cost
 291       t(2,3,i-2)= 0.0D0
 292       t(3,1,i-2)= 0.0D0
 293       t(3,2,i-2)= 0.0D0
 294       t(3,3,i-2)= 1.0D0
 295       r(1,1,i-2)= 1.0D0
 296       r(1,2,i-2)= 0.0D0
 297       r(1,3,i-2)= 0.0D0
 298       r(2,1,i-2)= 0.0D0
 299       r(2,2,i-2)=-cosphi
 300       r(2,3,i-2)= sinphi
 301       r(3,1,i-2)= 0.0D0
 302       r(3,2,i-2)= sinphi
 303       r(3,3,i-2)= cosphi
 304       rt(1,1,i-2)=-cost
 305       rt(1,2,i-2)=-sint
 306       rt(1,3,i-2)=0.0D0
 307       rt(2,1,i-2)=sint*cosphi
 308       rt(2,2,i-2)=-cost*cosphi
 309       rt(2,3,i-2)=sinphi
 310       rt(3,1,i-2)=-sint*sinphi
 311       rt(3,2,i-2)=cost*sinphi
 312       rt(3,3,i-2)=cosphi
 313       call matmult(prod(1,1,i-2),rt(1,1,i-2),prod(1,1,i-1))
 314       do j=1,3
 315         dc_norm(j,i-1)=prod(j,1,i-1)
 316         dc(j,i-1)=vbld(i)*prod(j,1,i-1)
 317         c(j,i)=c(j,i-1)+dc(j,i-1)
 318       enddo
 319 cd    print '(2i3,2(3f10.5,5x))', i-1,i,(dc(j,i-1),j=1,3),(c(j,i),j=1,3)
 320 C
 321 C Now calculate the coordinates of SC(i-1)
 322 C
 323       call locate_side_chain(i-1)
 324       return
 325       end
 326 c-----------------------------------------------------------------------------
 327       subroutine locate_side_chain(i)
 328 C
 329 C Locate the side-chain centroid i, 1 < i < NRES. Put in C(*,NRES+i).
 330 C
 331       implicit real*8 (a-h,o-z)
 332       include 'DIMENSIONS'
 333       include 'COMMON.CHAIN'
 334       include 'COMMON.LOCAL'
 335       include 'COMMON.GEO'
 336       include 'COMMON.VAR'
 337       include 'COMMON.IOUNITS'
 338       include 'COMMON.NAMES'
 339       include 'COMMON.INTERACT'
 340       dimension xx(3)
 341
 342 c      dsci=dsc(itype(i))
 343 c      dsci_inv=dsc_inv(itype(i))
 344       dsci=vbld(i+nres)
 345       dsci_inv=vbld_inv(i+nres)
 346 #ifdef OSF
 347       alphi=alph(i)
 348       omegi=omeg(i)
 349       if (alphi.ne.alphi) alphi=100.0
 350       if (omegi.ne.omegi) omegi=-100.0
 351 #else
 352       alphi=alph(i)
 353       omegi=omeg(i)
 354 #endif
 355       cosalphi=dcos(alphi)
 356       sinalphi=dsin(alphi)
 357       cosomegi=dcos(omegi)
 358       sinomegi=dsin(omegi)
 359       xp= dsci*cosalphi
 360       yp= dsci*sinalphi*cosomegi
 361       zp=-dsci*sinalphi*sinomegi
 362 * Now we have to rotate the coordinate system by 180-theta(i)/2 so as to get its
 363 * X-axis aligned with the vector DC(*,i)
 364       theta2=pi-0.5D0*theta(i+1)
 365       cost2=dcos(theta2)
 366       sint2=dsin(theta2)
 367       xx(1)= xp*cost2+yp*sint2
 368       xx(2)=-xp*sint2+yp*cost2
 369       xx(3)= zp
 370 cd    print '(a3,i3,3f10.5,5x,3f10.5)',restyp(itype(i)),i,
 371 cd   &   xp,yp,zp,(xx(k),k=1,3)
 372       do j=1,3
 373         xloc(j,i)=xx(j)
 374       enddo
 375 * Bring the SC vectors to the common coordinate system.
 376       xx(1)=xloc(1,i)
 377       xx(2)=xloc(2,i)*r(2,2,i-1)+xloc(3,i)*r(2,3,i-1)
 378       xx(3)=xloc(2,i)*r(3,2,i-1)+xloc(3,i)*r(3,3,i-1)
 379       do j=1,3
 380         xrot(j,i)=xx(j)
 381       enddo
 382       do j=1,3
 383         rj=0.0D0
 384         do k=1,3
 385           rj=rj+prod(j,k,i-1)*xx(k)
 386         enddo
 387         dc(j,nres+i)=rj
 388         dc_norm(j,nres+i)=rj*dsci_inv
 389         c(j,nres+i)=c(j,i)+rj
 390       enddo
 391       return
 392       end
 393 c------------------------------------------
 394       subroutine returnbox
 395       include 'DIMENSIONS'
 396 #ifdef MPI
 397       include 'mpif.h'
 398 #endif
 399       include 'COMMON.CONTROL'
 400       include 'COMMON.VAR'
 401       include 'COMMON.MD'
 402 #ifndef LANG0
 403       include 'COMMON.LANGEVIN'
 404 #else
 405       include 'COMMON.LANGEVIN.lang0'
 406 #endif
 407       include 'COMMON.CHAIN'
 408       include 'COMMON.DERIV'
 409       include 'COMMON.GEO'
 410       include 'COMMON.LOCAL'
 411       include 'COMMON.INTERACT'
 412       include 'COMMON.IOUNITS'
 413       include 'COMMON.NAMES'
 414       include 'COMMON.TIME1'
 415       include 'COMMON.REMD'
 416       include 'COMMON.SETUP'
 417       include 'COMMON.MUCA'
 418       include 'COMMON.HAIRPIN'
 419 C change suggested by Ana - begin
 420       integer allareout
 421 C change suggested by Ana - end
 422         j=1
 423         chain_beg=1
 424 C        do i=1,nres
 425 C       write(*,*) 'initial', i,j,c(j,i)
 426 C        enddo
 427 C change suggested by Ana - begin
 428         allareout=1
 429 C change suggested by Ana -end
 430         do i=1,nres-1
 431          if ((itype(i).eq.ntyp1).and.(itype(i+1).eq.ntyp1)) then
 432           chain_end=i
 433           if (allareout.eq.1) then
 434             ireturnval=int(c(j,i)/boxxsize)
 435             if (c(j,i).le.0) ireturnval=ireturnval-1
 436             do k=chain_beg,chain_end
 437               c(j,k)=c(j,k)-ireturnval*boxxsize
 438               c(j,k+nres)=c(j,k+nres)-ireturnval*boxxsize
 439             enddo
 440 C Suggested by Ana
 441             if (chain_beg.eq.1)
 442      &      dc_old(1,0)=dc_old(1,0)-ireturnval*boxxsize
 443 C Suggested by Ana -end
 444            endif
 445            chain_beg=i+1
 446            allareout=1
 447          else
 448           if (int(c(j,i)/boxxsize).eq.0) allareout=0
 449          endif
 450         enddo
 451          if (allareout.eq.1) then
 452             ireturnval=int(c(j,i)/boxxsize)
 453             if (c(j,i).le.0) ireturnval=ireturnval-1
 454             do k=chain_beg,nres
 455               c(j,k)=c(j,k)-ireturnval*boxxsize
 456               c(j,k+nres)=c(j,k+nres)-ireturnval*boxxsize
 457             enddo
 458           endif
 459 C NO JUMP
 460 C        do i=1,nres
 461 C        write(*,*) 'befor no jump', i,j,c(j,i)
 462 C        enddo
 463         nojumpval=0
 464         do i=2,nres
 465            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 466              difference=abs(c(j,i-1)-c(j,i))
 467 C             print *,'diff', difference
 468              if (difference.gt.boxxsize/2.0) then
 469                 if (c(j,i-1).gt.c(j,i)) then
 470                   nojumpval=1
 471                  else
 472                    nojumpval=-1
 473                  endif
 474               else
 475               nojumpval=0
 476               endif
 477               endif
 478               c(j,i)=c(j,i)+nojumpval*boxxsize
 479               c(j,i+nres)=c(j,i+nres)+nojumpval*boxxsize
 480          enddo
 481        nojumpval=0
 482         do i=2,nres
 483            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 484              difference=abs(c(j,i-1)-c(j,i))
 485              if (difference.gt.boxxsize/2.0) then
 486                 if (c(j,i-1).gt.c(j,i)) then
 487                   nojumpval=1
 488                  else
 489                    nojumpval=-1
 490                  endif
 491               else
 492               nojumpval=0
 493               endif
 494              endif
 495               c(j,i)=c(j,i)+nojumpval*boxxsize
 496               c(j,i+nres)=c(j,i+nres)+nojumpval*boxxsize
 497          enddo
 498
 499 C        do i=1,nres
 500 C        write(*,*) 'after no jump', i,j,c(j,i)
 501 C        enddo
 502
 503 C NOW Y dimension
 504 C suggesed by Ana begins
 505         allareout=1
 506 C suggested by Ana ends
 507         j=2
 508         chain_beg=1
 509         do i=1,nres-1
 510          if ((itype(i).eq.ntyp1).and.(itype(i+1).eq.ntyp1)) then
 511           chain_end=i
 512           if (allareout.eq.1) then
 513             ireturnval=int(c(j,i)/boxysize)
 514             if (c(j,i).le.0) ireturnval=ireturnval-1
 515             do k=chain_beg,chain_end
 516               c(j,k)=c(j,k)-ireturnval*boxysize
 517              c(j,k+nres)=c(j,k+nres)-ireturnval*boxysize
 518             enddo
 519 C Suggested by Ana
 520             if (chain_beg.eq.1)
 521      &      dc_old(1,0)=dc_old(1,0)-ireturnval*boxxsize
 522 C Suggested by Ana -end
 523            endif
 524            chain_beg=i+1
 525            allareout=1
 526          else
 527           if (int(c(j,i)/boxysize).eq.0) allareout=0
 528          endif
 529         enddo
 530          if (allareout.eq.1) then
 531             ireturnval=int(c(j,i)/boxysize)
 532             if (c(j,i).le.0) ireturnval=ireturnval-1
 533             do k=chain_beg,nres
 534               c(j,k)=c(j,k)-ireturnval*boxysize
 535               c(j,k+nres)=c(j,k+nres)-ireturnval*boxysize
 536             enddo
 537           endif
 538         nojumpval=0
 539         do i=2,nres
 540            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 541              difference=abs(c(j,i-1)-c(j,i))
 542              if (difference.gt.boxysize/2.0) then
 543                 if (c(j,i-1).gt.c(j,i)) then
 544                   nojumpval=1
 545                  else
 546                    nojumpval=-1
 547                  endif
 548              else
 549               nojumpval=0
 550               endif
 551            endif
 552               c(j,i)=c(j,i)+nojumpval*boxysize
 553               c(j,i+nres)=c(j,i+nres)+nojumpval*boxysize
 554          enddo
 555       nojumpval=0
 556         do i=2,nres
 557            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 558              difference=abs(c(j,i-1)-c(j,i))
 559              if (difference.gt.boxysize/2.0) then
 560                 if (c(j,i-1).gt.c(j,i)) then
 561                   nojumpval=1
 562                  else
 563                    nojumpval=-1
 564                  endif
 565               else
 566               nojumpval=0
 567               endif
 568             endif
 569               c(j,i)=c(j,i)+nojumpval*boxysize
 570               c(j,i+nres)=c(j,i+nres)+nojumpval*boxysize
 571          enddo
 572 C Now Z dimension
 573 C Suggested by Ana -begins
 574         allareout=1
 575 C Suggested by Ana -ends
 576        j=3
 577         chain_beg=1
 578         do i=1,nres-1
 579          if ((itype(i).eq.ntyp1).and.(itype(i+1).eq.ntyp1)) then
 580           chain_end=i
 581           if (allareout.eq.1) then
 582             ireturnval=int(c(j,i)/boxysize)
 583             if (c(j,i).le.0) ireturnval=ireturnval-1
 584             do k=chain_beg,chain_end
 585               c(j,k)=c(j,k)-ireturnval*boxzsize
 586               c(j,k+nres)=c(j,k+nres)-ireturnval*boxzsize
 587             enddo
 588 C Suggested by Ana
 589             if (chain_beg.eq.1)
 590      &      dc_old(1,0)=dc_old(1,0)-ireturnval*boxxsize
 591 C Suggested by Ana -end
 592            endif
 593            chain_beg=i+1
 594            allareout=1
 595          else
 596           if (int(c(j,i)/boxzsize).eq.0) allareout=0
 597          endif
 598         enddo
 599          if (allareout.eq.1) then
 600             ireturnval=int(c(j,i)/boxzsize)
 601             if (c(j,i).le.0) ireturnval=ireturnval-1
 602             do k=chain_beg,nres
 603               c(j,k)=c(j,k)-ireturnval*boxzsize
 604               c(j,k+nres)=c(j,k+nres)-ireturnval*boxzsize
 605             enddo
 606           endif
 607         nojumpval=0
 608         do i=2,nres
 609            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 610              difference=abs(c(j,i-1)-c(j,i))
 611              if (difference.gt.(boxzsize/2.0)) then
 612                 if (c(j,i-1).gt.c(j,i)) then
 613                   nojumpval=1
 614                  else
 615                    nojumpval=-1
 616                  endif
 617               else
 618               nojumpval=0
 619               endif
 620             endif
 621               c(j,i)=c(j,i)+nojumpval*boxzsize
 622               c(j,i+nres)=c(j,i+nres)+nojumpval*boxzsize
 623          enddo
 624        nojumpval=0
 625         do i=2,nres
 626            if (itype(i).eq.ntyp1 .and. itype(i-1).eq.ntyp1) then
 627              difference=abs(c(j,i-1)-c(j,i))
 628              if (difference.gt.boxzsize/2.0) then
 629                 if (c(j,i-1).gt.c(j,i)) then
 630                   nojumpval=1
 631                  else
 632                    nojumpval=-1
 633                  endif
 634               else
 635               nojumpval=0
 636               endif
 637             endif
 638              c(j,i)=c(j,i)+nojumpval*boxzsize
 639               c(j,i+nres)=c(j,i+nres)+nojumpval*boxzsize
 640          enddo
 641
 642         return
 643         end
 644