source/unres/src_MD-M/intcor.f

   1 C
   2 C------------------------------------------------------------------------------
   3 C
   4       double precision function alpha(i1,i2,i3)
   5 c
   6 c  Calculates the planar angle between atoms (i1), (i2), and (i3).
   7 c
   8       implicit real*8 (a-h,o-z)
   9       include 'DIMENSIONS'
  10       include 'COMMON.GEO'
  11       include 'COMMON.CHAIN'
  12       x12=c(1,i1)-c(1,i2)
  13       x23=c(1,i3)-c(1,i2)
  14       y12=c(2,i1)-c(2,i2)
  15       y23=c(2,i3)-c(2,i2)
  16       z12=c(3,i1)-c(3,i2)
  17       z23=c(3,i3)-c(3,i2)
  18       vnorm=dsqrt(x12*x12+y12*y12+z12*z12)
  19       wnorm=dsqrt(x23*x23+y23*y23+z23*z23)
  20       scalar=(x12*x23+y12*y23+z12*z23)/(vnorm*wnorm)
  21       alpha=arcos(scalar)
  22       return
  23       end
  24 C
  25 C------------------------------------------------------------------------------
  26 C
  27       double precision function beta(i1,i2,i3,i4)
  28 c
  29 c  Calculates the dihedral angle between atoms (i1), (i2), (i3) and (i4)
  30 c
  31       implicit real*8 (a-h,o-z)
  32       include 'DIMENSIONS'
  33       include 'COMMON.GEO'
  34       include 'COMMON.CHAIN'
  35       include 'COMMON.IOUNITS'
  36       x12=c(1,i1)-c(1,i2)
  37       x23=c(1,i3)-c(1,i2)
  38       x34=c(1,i4)-c(1,i3)
  39       y12=c(2,i1)-c(2,i2)
  40       y23=c(2,i3)-c(2,i2)
  41       y34=c(2,i4)-c(2,i3)
  42       z12=c(3,i1)-c(3,i2)
  43       z23=c(3,i3)-c(3,i2)
  44       z34=c(3,i4)-c(3,i3)
  45 cd    print '(2i3,3f10.5)',i1,i2,x12,y12,z12
  46 cd    print '(2i3,3f10.5)',i2,i3,x23,y23,z23
  47 cd    print '(2i3,3f10.5)',i3,i4,x34,y34,z34
  48       wx=-y23*z34+y34*z23
  49       wy=x23*z34-z23*x34
  50       wz=-x23*y34+y23*x34
  51       wnorm=dsqrt(wx*wx+wy*wy+wz*wz)
  52       vx=y12*z23-z12*y23
  53       vy=-x12*z23+z12*x23
  54       vz=x12*y23-y12*x23
  55       vnorm=dsqrt(vx*vx+vy*vy+vz*vz)
  56       if (vnorm.gt.1.0D-13 .and. wnorm.gt.1.0D-13) then
  57       scalar=(vx*wx+vy*wy+vz*wz)/(vnorm*wnorm)
  58       if (dabs(scalar).gt.1.0D0)
  59      &scalar=0.99999999999999D0*scalar/dabs(scalar)
  60       angle=dacos(scalar)
  61       else
  62       angle=pi
  63       endif
  64 c     if (angle.le.0.0D0) angle=pi+angle
  65       tx=vy*wz-vz*wy
  66       ty=-vx*wz+vz*wx
  67       tz=vx*wy-vy*wx
  68       scalar=tx*x23+ty*y23+tz*z23
  69       if (scalar.lt.0.0D0) angle=-angle
  70       beta=angle
  71 cd      if ((vnorm.lt.0.01.or.wnorm.lt.0.01).and.angle.ne.pi
  72 cd     & .and.i3.ne.maxres*2)
  73 cd     & write(iout,'(a12,4i4,6f7.3,4f10.5)') 'beta warning',i1,i2,i3,i4,
  74 cd     & vx,vy,vz,wx,wy,wz,vnorm,wnorm,scalar,angle*RAD2DEG
  75       return
  76       end
  77 C
  78 C------------------------------------------------------------------------------
  79 C
  80       function dist(i1,i2)
  81 c
  82 c  Calculates the distance between atoms (i1) and (i2).
  83 c
  84       implicit real*8 (a-h,o-z)
  85       include 'DIMENSIONS'
  86       include 'COMMON.GEO'
  87       include 'COMMON.CHAIN'
  88       x12=c(1,i1)-c(1,i2)
  89       y12=c(2,i1)-c(2,i2)
  90       z12=c(3,i1)-c(3,i2)
  91       dist=dsqrt(x12*x12+y12*y12+z12*z12)
  92       return
  93       end
  94 C