[gmx-users] TIP3P versus SPC?

[David]

On Tue, 2003-02-18 at 14:17, Alan Wilter Sousa da Silva wrote:
> Hi Michael,
> 
> 	I always want to do something like that so, if you allowed me, I
> would like to suggest you testing also SPCE water.
> 
> 	That would be very appreciated.
> 
> 	Thanks in advance.
> 
> Cheers
> 
> On Mon, 17 Feb 2003, Michael Shirts wrote:
> 
> >
> > Hi, all - I was just wondering about the differences of implementation of
> > TIP3P and SPC in GROMACS.  I get a couple of odd things - below are outputs of
> > g_energy from two simulations, identical conditions except that one has TIP3P
> > and the other has SPC.  PME, rlist = rcoulomb = 1.15, Switched VdW 0.9-1.1,
> > dispersion correction, 900 molecules, Nose-Hoover, Parrinello-Rahman.
> >
> > The densities remain close to the experimental values, but the coulombic
> > energy for TIP3P is 20x that of SPC. Do you have any idea why this is the
> > case?  It just seems rather odd that this differece in coulombic energy should
> > exist without there being other large differences in other properties. . .
> 
Just checking: you're not running an old version of gmx on an Athlon,
are you?

Apropos SPC/E (and other water models) there are a number of tests in
the literature...

-- 
Groeten, David.
________________________________________________________________________
Dr. David van der Spoel, 	Dept. of Cell and Molecular Biology
Husargatan 3, Box 596,  	75124 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://xray.bmc.uu.se/~spoel
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