On 2011-04-21 03:54:09AM -0500, Jianguo Li wrote: > Dear all, > > My molecule contains -CH=CH- fragment and I am trying to create the topology > using Charmm FF. It seems that there is no improper dihedrals for -CH=CH- > fragment in Charmm FF, while other FF (e.g., Amber or OPLS) has additional > improper dihedrals terms for that fragment. > Could anybody confirm this?
AFAIK, CHARMM only defines impropers for planar fragments not linear ones... (based on my reading of CGenFF2b6) This sort of makes sense since in a linear structure, normal dihedrals are already defined for every meaningful combination... -- ================================================================== Peter C. Lai | University of Alabama-Birmingham Programmer/Analyst | BEC 257 Genetics, Div. of Research | 1150 10th Avenue South [email protected] | Birmingham AL 35294-4461 (205) 690-0808 | ================================================================== -- gmx-users mailing list [email protected] http://lists.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to [email protected]. Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
