[gmx-users] Water models and force fields

[David]

On Mon, 2002-07-08 at 11:13, Mehmet Suezen wrote:
> Lieven Buts wrote:
> > 
> > Anton Feenstra wrote:
> > > Lieven Buts wrote:
> > > >   Does this have any implications for the choice of water model
> > > > in GROMACS?
> > >
> > > Indeed. The forcefields available in Gromacs (i.e. gmx* & G43*)
> > > were designed for and with SPC or SPC/E. These two water models
> > > are to a large extent interchangable where SPC is slightly more
> > > accurate in a dynamical sense, and SPC/E in a thermodynamical
> > > sense (i.e. on averages etc.).
> > 
> > And what about the newly introduced OPLS-AA, which was developed by
> > the Jorgensen group, which also developed the TIP water models?
> >
This is a difficult topic, only testing can give you the answer. We have
done some tests for peptides in different water models (J. Biomol. NMR
8, (1996) 229-238) and for pure water in different models (JCP 108
(1998) 10220-10230). There are some other published comparisons too In
general TIP3P should be avoided, TIP4P and SPC are decent, whereas SPC/E
and TIP5P are only suitable for highly polar systems such pure water or
maybe salt solutions.

I'm currently running the OPLSAA force field with SPC.

-- 
Groeten, David.
________________________________________________________________________
Dr. David van der Spoel, 	Biomedical center, Dept. of Biochemistry
Husargatan 3, Box 576,  	75123 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://zorn.bmc.uu.se/~spoel
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