source/unres/src_MD/src/md-diff/np/verlet1.f

   1 c-----------------------------------------------------------------
   2       subroutine verlet1
   3 c Applying velocity Verlet algorithm - step 1 to coordinates
   4       implicit real*8 (a-h,o-z)
   5       include 'DIMENSIONS'
   6       include 'COMMON.CONTROL'
   7       include 'COMMON.VAR'
   8       include 'COMMON.MD'
   9       include 'COMMON.CHAIN'
  10       include 'COMMON.DERIV'
  11       include 'COMMON.GEO'
  12       include 'COMMON.LOCAL'
  13       include 'COMMON.INTERACT'
  14       include 'COMMON.IOUNITS'
  15       include 'COMMON.NAMES'
  16       double precision adt,adt2
  17
  18       do j=1,3
  19         adt=d_a_old(j,0)*d_time
  20         adt2=0.5d0*adt
  21         dc(j,0)=dc_old(j,0)+(d_t_old(j,0)+adt2)*d_time
  22         d_t_new(j,0)=d_t_old(j,0)+adt2
  23         d_t(j,0)=d_t_old(j,0)+adt
  24       enddo
  25       do i=nnt,nct-1
  26         do j=1,3
  27           adt=d_a_old(j,i)*d_time
  28           adt2=0.5d0*adt
  29           dc(j,i)=dc_old(j,i)+(d_t_old(j,i)+adt2)*d_time
  30           d_t_new(j,i)=d_t_old(j,i)+adt2
  31           d_t(j,i)=d_t_old(j,i)+adt
  32         enddo
  33       enddo
  34       do i=nnt,nct
  35         if (itype(i).ne.10) then
  36           inres=i+nres
  37           do j=1,3
  38             adt=d_a_old(j,inres)*d_time
  39             adt2=0.5d0*adt
  40             dc(j,inres)=dc_old(j,inres)+(d_t_old(j,inres)+adt2)*d_time
  41             d_t_new(j,inres)=d_t_old(j,inres)+adt2
  42             d_t(j,inres)=d_t_old(j,inres)+adt
  43           enddo
  44         endif
  45       enddo
  46       return
  47       end