[gmx-users] charges

[Anton Feenstra]

Coincon Mathieu wrote:

> Hi,
> 
> I know that this topic is generously covered by the FAQ archives but it
> looks like everyone has his own answer.
> So what's the best way to determine partial charges for a new topology ?
> 
> QM?
> homology with groups in ff*.rtp?
> PRODRG?
> Fortune telling?

In the Gromacs & Gromos ff's charges are parameters that are needed to
reproduce experimental values. For solvents you could look at, e.g.,
dipole moments, dielectric constant, and so on, but also density and
heat of vaproization should still be good. The best way is to find the
most sensitive experimental data measured at best accuracy, and modify
your charges to reproduce the data...

But that is a lot of work, so most people I know have their own,
simple, pragmatic approach...


-- 
Groetjes,

Anton
  _____________ _______________________________________________________
|             |                                                       |
|  _   _  ___,| K. Anton Feenstra                                     |
| / \ / \'| | | Dept. of Pharmacochem. - Vrije Universiteit Amsterdam |
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| \_/ \_/ | | | Tel: +31 20 44 47608 - Fax: +31 20 44 47610           |
|             | Feenstra at chem.vu.nl - www.chem.vu.nl/~feenstra/       |
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