Re: TIP4P/Ice usage in NAMD

From: Peter Freddolino (
Date: Tue Aug 24 2010 - 09:14:39 CDT

Hi Ravi,
You should be able to do this by editing the oxygen-lone pair bond
distance and oxygen LJ terms in the parameter file, and the charges in
the topology file. The Right Way (tm) to do this is to duplicate the
TIP4P residue and all the associated atom types, make a new residue name
(and associated type names) for TIP4/Ice, and then edit the duplicated
versions. The topology and parameter file tutorials at should be helpful in finding
where those particular quantities are kept. Let me know if you run into

On 08/24/2010 04:22 AM, Ravinder Abrol wrote:
> Hi,
> I would like to use the TIP4P/Ice model to simulate water/ice at 273K.
> Anyone has experience in using it within NAMD?
> I can find parameters for TIP4P in par_all30_* and top_all30_* files, but it
> is not obvious what to change in those files to use the TIP4P/Ice parameters
> described in Abascal et al., J Chem Phys 122, 234511 (2005).
> Thanks,
> Ravi

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