6.5 Program 6.1, Fortran Code
97
acvsq = 0.0
flv = 0.0
acr = 0.0
acrsq = 0.0
flr = 0.0
acdiff = 0.0
acdiffx =0.0
acrot = 0.0
vcx = 0.0
SUMR = 0.0
SUMR2 = 0.0
Ein=0.
work=0.
sumFrat =0.
sumvcx=0.
sumvcx2=0.
sumvcy=0.
sumvcz = 0.
sumvc = 0.
c ** write out some useful information **
write(4,’(” dt = ”,f10.5)’) dt
write(4,’(/” ** brownian dynamics begins ** ”/ )’)
c write(4,’(” step v/n ”/ )’)
c *********************************************************
c ** main loop begins **
c *********************************************************
c ** calculate the diffusion tensor and systematic **
c ** forces at the beginning of the step **
do i = 1, n
rx0(i) = rx(i)
ry0(i) = ry(i)
rz0(i) = rz(i) end do
rcx0 = (rx0(1)+rx0(2))*0.5
rcy0 = (ry0(1)+ry0(2))*0.5
rcz0 = (rz0(1)+rz0(2))*0.5
rx210 = rx0(2)-rx0(1)
ry210 = ry0(2)-ry0(1)
rz210 = rz0(2)-rz0(1)
r21sq0 = rx210*rx210 + ry210*ry210 + rz210*rz210
r210 = sqrt(r21sq0)
A = 7.
Fload = -1
gamma = 0.1
mass=2.
w = 5.