Hi, That behaviour might depend on what your starting configuration is, e.g. what group MOL has frozen coordinates. But cut-off is anyway a ~useless model for condensed phase of atoms with partial charges, so understanding the issue hasn't got much value.
Mark On Mon, May 18, 2015 at 3:58 AM niexuechuan <niexuech...@126.com> wrote: > Hi everyone, > I found that after gromacs version 4.6, when set > "cutoff-scheme=Verlet" and "coulombtype= cut-off", the waters in the system > will freeze into ice. I known that charge-groups are necessary when using > plain cut-off electrostatics. But I'm surprised that why the waters freeze > into ice when using plain cut-off electrostatics without charge-groups? > Could someone explain how it happenes? > > > My mdp files are like this: > > > integrator = md > constraints = all_bonds > dt = 0.002 > nsteps = 50000000 > comm-mode =None > nstxout = 0 > nstvout = 0 > nstfout = 0 > nstlog = 25000 > nstxtcout = 500 > xtc-precision = 1000 > energygrps = MOL SOL > nstlist = 1 > ns_type = grid > pbc = xyz > rlist = 1.0 > coulombtype = cut-off > rcoulomb-switch = 0 > rcoulomb = 1.0 > vdw-type = cut-off > rvdw-switch = 0 > rvdw = 1.0 > Tcoupl = V-rescale > nsttcouple = -1 > tc-grps = MOL SOL > tau_t = 0.1 0.1 > ref_t = 300 300 > freezegrps = MOL > freezedim = Y Y Y > > Thanks! > Xuechuan > -- > 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.