Hi Dan and all guys, Thanks for your answers. I find that the OPLS-AA force field does not contain the dihedral force-field parameters of the Chain_C. Actually, my Chain_C was a hydroxyapatite (HAP, inorganic material) model. I also notice that the bond types of HAP in the ffbonded.itp file are missing. Following are some parameters from my ffbonded.itp file. [ dihedraltypes ] ; i j k l func coefficients C3 CT NT C3 3 1.78866 3.49154 0.53555 -5.81576 0.00000 0.00000 ; (From wildcard) amine all-atom [ bondtypes ] ; i j func b0 kb OW HW 1 0.09572 502080.0 ; For TIP4F Water - wlj 1/98 My question is that what are the meanings of the i, j, k, l, func, coefficients, b0, and kb? How to find the values of those of HAP? Just list some [bonds] and [dihedrals] of my Chain_C as follows. [ bonds ] O1 P27 O10 P27 O13 P27 O14 P27 O2 P28 [ dihedrals ] O1 P27 O10 O13 O1 P27 O10 O14 O1 P27 O13 O10 O1 P27 O13 O14 O1 P27 O14 O13 Thanks for your time and any suggestions. Kind regards, Baolin ------------------ Original ------------------ From: "Dan Gil"<dan.gil9...@gmail.com>; Date: Tue, Aug 14, 2018 04:39 AM To: "gmx-users"<gmx-us...@gromacs.org>;
Subject: Re: [gmx-users] No default Ryckaert-Bell. types Hello, This is telling you that the OPLS-AA force field does not have the dihedral force-field parameters for your molecule (topol_Other_chain_C.itp) of the Ryckaert-Bell type. Your exact problem might be: (1) There is something wrong with the molecule topology. (2) OPLS-AA really doesn't have the dihedral force-field parameters, and you need to use another force-field. If your molecule is a simple hydrocarbon, it is unlikely that OPLS-AA has missing parameters. Dan On Sat, Aug 11, 2018 at 10:52 AM, Baolin Huang <hb...@gzhu.edu.cn> wrote: > Dear All, > I experienced an error as follows: (I used the OPLS-AA force field) > ERROR 48600 [file topol_Other_chain_C.itp, line 144934]: > No default Ryckaert-Bell. types > > > Anyone can help? > Kind regards, > > > ------------------ > > Dr. Baolin Huang > Lecturer, School of Life Sciences, Guangzhou University > -- > 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. > -- 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. -- 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.