[gmx-users] Chloride parameters in ffgmx
feenstra at chem.vu.nl
Mon Apr 28 16:48:01 CEST 2003
hugo verli wrote:
> The charges were obtained from Ab-initio calculations and the topology for the
> chloroform made in PRODRG site.
> Any suggestion? Could this error be due to atomic charges or to van der Waals
> parameters (form chloride ion and not for covalent bound chlorine)?
There is already chloroform in the Gromos forcefield, isn't it also
already in the Gromacs? If not, you could probably simply take the
Gromos parameters, at least for a good start.
Ab-initio charges are usually (a lot) higher than those used in the
Gromos/Gromacs forcefields, for example, from page IV-271 GromOS
manual, Cl charges are -0.087, C is 0.179 and H is 0.08. You can
compare these to the charges you found from Ab-initio.
| | |
| _ _ ___,| K. Anton Feenstra |
| / \ / \'| | | Dept. of Pharmacochem. - Vrije Universiteit Amsterdam |
|( | )| | | De Boelelaan 1083 - 1081 HV Amsterdam - Netherlands |
| \_/ \_/ | | | Tel: +31 20 44 47608 - Fax: +31 20 44 47610 |
| | Feenstra at chem.vu.nl - www.chem.vu.nl/~feenstra/ |
| | "If You See Me Getting High, Knock Me Down" |
| | (Red Hot Chili Peppers) |
More information about the gromacs.org_gmx-users