I often use 4 fs with all-bonds and virtual sites, especially if lacking sampling is a greater source of error than the kinetic energy being slightly off.
Erik On 15 Aug 2013, at 20:58, Michael Shirts <mrshi...@gmail.com> wrote: > I don't go beyond 2 fs with either all- bonds or h-bonds. Things like kinetic > energy start being subtly off. > > H-bonds has less chance of failing with large numbers of constraints- less > iteration required, especially if bond system cross parallelization > boundaries. > > If your molecules are < 10 atoms, it probably doesn't matter either way. > > Sent from my iPhone > > On Aug 15, 2013, at 9:11, "Barnett, James W." <jbarn...@tulane.edu> wrote: > >> Searching through this mailing list it seems like some have stated that >> with a 2 fs timestep (dt=0.002), constraints=h-bonds is fine in general. >> >> The questions I have are: >> >> 1) What are some personal opinions on when it is ok to switch to h-bonds >> from all-bonds for LINCS constraints? Is 2 fs and h-bonds a general >> practice? >> >> 2) Also, if typically 2 fs and h-bonds are ok, what time-step do users >> (or you personally) generally go to with all-bonds? >> >> I am speaking generally here of course. Thanks for your responses. >> >> -- >> Wes Barnett | jbarn...@tulane.edu >> >> -- >> 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 > -- > 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 -- 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
