rlist 1.3 did the trick, thanks. Why did I not see this problem with PME-switch? Thanks,
Ilya 2009/4/1 Berk Hess <g...@hotmail.com> > > > > Date: Wed, 1 Apr 2009 14:15:05 +1100 > > From: mark.abra...@anu.edu.au > > To: gmx-users@gromacs.org > > Subject: Re: [gmx-users] Energy Conservation with 4fs timestep > > > > Joe Joe wrote: > > > Hi, > > > > > > I get good conservation when running NVE in gromacs with 4 fs when I > use > > > PME-switch for electrostatics but not so good when I use switch. Any > > > thoughts why that would be? Params shown below. > > > > Finite cutoffs (such as used with "switch") are intrinsically unlikely > > to conserve energy. > > > > Mark > > That is not right. > Finite cut-off's such as switch and shift are purposely designed to > conserve energy. > Switch is not particularly good though, since the switching introduces > large forces. > I would advise to use PME-switch or reaction-field-zero for electrostatics > and shift for vdw. > > But the main problem in your setup seems to be the 0.1 nm buffer between > the cut-off > and rlist. In general you will need a buffer of 0.25 to 0.3 nm. > You can use rlist=-1 to get exact integration and then vary rlist to get a > reasonable > neighborlist update frequency (somewhere around 10 steps). > We should automate the choice of rlist such that the user does not need to > worry > about this. > > Berk > > > > > ------------------------------ > Express yourself instantly with MSN Messenger! MSN > Messenger<http://clk.atdmt.com/AVE/go/onm00200471ave/direct/01/> > > _______________________________________________ > 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 gmx-users-requ...@gromacs.org. > Can't post? Read http://www.gromacs.org/mailing_lists/users.php >
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