'The force is not the derivative of the potential', is it due to the types of calculations performed in PME, using of FFT for reciprocal sum? Because it does not matter while using reaction-field method. Sorry, this phenomenon is a little complicated to me :)
Thanks for your attention! Oz. -----Original Message----- From: David van der Spoel <[EMAIL PROTECTED]> To: Discussion list for GROMACS users <gmx-users@gromacs.org> Date: Sat, 01 Sep 2007 13:37:05 +0200 Subject: Re: [gmx-users] r_list and r_coulomb values while using PME OZGE ENGIN wrote: > Hi all, > > I can not understand why it is required to take same values for both r_list > and r_coulomb parameters when using PME for calculation of electrostatic > interactions? > > I read archieve, and gromacs manual. In archieve, similar question had been > posted, but not replied yet. > > Thanks in advance if rlist < rcoulomb you will have a twin range interaction, meaning the atom pair interactions for distance between these two will be computed every nstlist steps only, while the interaction beyond rcoulomb will be computed at each time step. this will lead to bad energy conservation, since the force is not the derivative of the potential. > > Oz. > > _______________________________________________ > gmx-users mailing list gmx-users@gromacs.org > http://www.gromacs.org/mailman/listinfo/gmx-users > Please search the archive at http://www.gromacs.org/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/mailing_lists/users.php -- David van der Spoel, Ph.D. Molec. Biophys. group, Dept. of Cell & Molec. Biol., Uppsala University. Box 596, 75124 Uppsala, Sweden. Phone: +46184714205. Fax: +4618511755. [EMAIL PROTECTED] [EMAIL PROTECTED] http://folding.bmc.uu.se _______________________________________________ gmx-users mailing list gmx-users@gromacs.org http://www.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/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/mailing_lists/users.php _______________________________________________ gmx-users mailing list gmx-users@gromacs.org http://www.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/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/mailing_lists/users.php