Thanks for your reply, Justin! I knew that gmx use as the follows for opls aa: -------------------- ; Improper OPLS dihedrals to keep groups planar. ; (OPLS doesnt use impropers for chiral atoms). ; Since these functions are periodic of the form 1-cos(2*x), they are actually ; implemented as proper dihedrals [1+cos(2*x+180)] for the moment, ; to keep things compatible. ; The defines are used in ffoplsaa.rtp or directly in your .top file.
; O?-C -X -Y improper torsion. C can be C_2 or C_3 too. #define improper_O_C_X_Y 180.0 43.93200 2 -------------------- But if it is possible to choose the function type: harmonic type (f.t y. =2) Where to assign function type number? Thanks! Tao On Mon, Jan 7, 2013 at 7:48 PM, <gmx-users-requ...@gromacs.org> wrote: > Re: help with improper angle in gmx (Justin Lemkul) -- gmx-users mailing list gmx-users@gromacs.org 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 gmx-users-requ...@gromacs.org. * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
