Page 373 - Handbook Of Multiphase Flow Assurance

372 10. Research methods in flow assurance

c it's an oxygen
if(iatomtype(natm,1).eq.3.and.natm.ne.chain(nbackbone-1))then
c check that it isn't a side group oxygen - that it isn't -OH
if(iatomtype(chain(nbackbone-1),1).ne.3.and.
& iatomtype(ibonddata(natm,1) ,1).ne.1.and.
& iatomtype(ibonddata(natm,2) ,1).ne.1) then
morecanfind=1
nbackbone=nbackbone+1
chain(nbackbone)=ibonddata(chain(nbackbone-1),i)
goto 30
endif
endif
end do
30 if(morecanfind.eq.1) goto 25
C
atmono=nbackbone/ngroups
if(atmono.ne.int(atmono)) then
print *,'Non-integer number of backbone atoms per monomer'
print *,'Please input this number (e.g. 2 for a vinyl chain)'
read (*,*)atmono
endif
C assign numbers to backbone atoms
do i=1,nbackbone
nmono =i
c =int(i/atmono+0.5D0) - this formula can be used to assign monomer numbers
iatomtype(chain(i),2)=nmono
c assign monomer numbers to backbone nearest neighbors
do j=1,nbonds(chain(i))
natm =ibonddata(chain(i),j)
c check that the backbone neighbor isn't a next/previous backbone atom
ibone=0
do k=1,nbackbone
if(natm.eq.chain(k))ibone=1
end do
if(ibone.eq.0) then
iatomtype(natm,2)=nmono
c assign monomer numbers to side groups
c if it's not a hydrogen, and atom isn't in backbone, it's a side group
if(iatomtype(natm,1).ne.1) then
c reset counters of atom being tested and those waiting for testing
ntest=1
nwait=1
c store the side group first atom as nside
nside=natm
listwait(nwait)=nside