[gmx-developers] Re: Amber to Gromacs forcefield conversion

[Anton Feenstra]

B.Hess at chem.rug.nl wrote:

> Erik Lindah wrote:
>
> > Graham Smith wrote:
> > 
> > > As you say, the impropers aren't right yet - the angle and force constant
> > > are the wrong way round. More worryingly, these are just the impropers for
> > > pi-bonding: the impropers that maintain the geometry of chiral centres are
> > > missing, and I can't see them in the amber force field files either - are
> > >
[..snip..]
> >
> > I don't think you need them with the all-atom force field. At least
> > that's the case with OPLS-aa;
[..snip..]
> 
> This is not really a question of needing.
> If they are in the original forcefield they should also be in Gromacs
> as they do influence the potential.

With respect to that, they are not defined in the Amber forcefield
(as Graham already mentioned), so it makes sense that they don't show 
up in the converted version.

By the way, I am very pleased that there apparently is so much interest
in this and with the enthousiasm with which you are looking at the 
results of my efforts ;-) !

-- 
Groetjes,

Anton
 ________ ___________________________________________________________
|        | Anton Feenstra                                            |
| .      | Dept. of Pharmacochemistry - Free University Amsterdam    |
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