CHARMM is generally used with vdw switching between 1.0 and 1.2 nm - I presume it must be more accurate that way. There are a number of discussions on this already. Justin recommended using rlistlong 1.4 as well I think. You might want to use a short range cutoff (rcoulomb) of 1.2 for PME as well. That is what was done in the Bjelkmar et al paper where CHARMM27 was implemented in GROMACS (http://pubs.acs.org/doi/full/10.1021/ct900549r).
Best wishes James On 24 Aug 2013, at 23:08, Gianluca Interlandi <gianl...@u.washington.edu> wrote: > Hi! > > I am running explicit solvent simulations with the CHARMM force field > implemented in gromacs 4.6.3. For VDW I have been using: > > rlist = 1.0 > vdw-type = Cut-off > rvdw = 1.0 > > in conjunction with PME and rcoulomb=1 for electrostatics. > > I wonder whether it would be more accurate to use instead a switching > function for VDW between 0.8 and 1.0 and a larger rlist: > > rlist = 1.2 > vdw-type = Switch > rvdw_switch = 0.8 > rvdw = 1.0 > > My question is: does switching between 0.8 and 1.0 generate less artifacts > than abrupt truncation at 1.0 nm for VDW? > > Thanks! > > Gianluca > > ----------------------------------------------------- > Gianluca Interlandi, PhD gianl...@u.washington.edu > http://artemide.bioeng.washington.edu/ > > Research Scientist at the Department of Bioengineering > at the University of Washington, Seattle WA U.S.A. > ----------------------------------------------------- > -- > 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
