Hi Mark, Thanks for you valuable advice. Your advice about tabulated entry was very helpful. As you said I read chapter 4 and 5 of manual. Since the equation used in the paper doesn't match any of the standard type mentioned in the manual, I have to use tabulated entry. I have 2 question in this regard.
1) As mentioned in the manual I have to make a .xvg file with 3 column and value of x (in my case angle) should be equally spaced. I just want to know what should be the ideal spacing. Is 10 degree increment or I should go for 1 degree? 2) In the paper they apply angular potential (v(x)=1.3(1+cos(x)))) between the plane defined by atom 1, 2, 3 and 3, 4, 5. I couldn't understand how to mention this in topology. All dihedral involves 4 atoms but here I have 5 atom. 1---2 \ 3 --- 4 \ 5 Thank you for your time and effort. "A society with free knowledge is better than a society with free food" Tushar Ranjan Moharana B. Tech, NIT Warangal Ph D Student, CCMB -- Gromacs Users mailing list * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before posting! * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists * For (un)subscribe requests visit https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or send a mail to gmx-users-requ...@gromacs.org.