On Sat, Feb 15, 2014 at 10:47 PM, CipPruteanu <c.prute...@ed.ac.uk> wrote: > Dr. Vitaly Chaban wrote >> I like extreme conditions... Seriously. >> >> OPLS water, as well as other popular MM waters, are parametrized for >> liquid state. I think you need to decrease model's dipole moment and >> you have to work with an integration time-step to ensure adequate >> energy conservation at ca. 600K. >> >> I believe there should be exotic water models that were trained to >> reproduce the phase diagram to certain extent. > > Dear Vitaly, > > I am aware of the fact that GROMACS "doesn't really like" crystal structure, > but this is generally fine with me since I run my simulations in a region > which is experimentally know to be liquid state (both the water and > methane). I am aware t hat it works best with liquids, and that is very well > since it is exactly the liquid phases of the mixture that I'm interested > in.
At 600K and under 25kbar ... water&methane mixture ... liquid state .... Hmmmm. Did you point out incorrect pressure? > The energy conservation looks fine throughout the whole 10 ns of most of my > simulations, however I'm not quite sure about how to decrease the dipole > moment of the model (or where exactly to do this, i.e. in which file). If > you can provide any suggestions on how to do this I would be more than > grateful. It is not that easy. You should first compute water's dipole moment for the simulated conditions. > The same applies for the more exotic water models. Unfortunately most people > around me using GROMACS work on biological systems, and I'm the only black > sheep trying to use it under extreme conditions. I will look for water > models trained for extreme conditions, but from my initial overview of the > literature there hardly seemed to be any. Something should exist. I hear such statements from different people from time to time. Dr. Vitaly V. Chaban -- 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.
