[gmx-users] modify C6 directly in FF using sigma and epsilon

[Ryogo Sugitani]

2007/4/5, David van der Spoel <spoel at xray.bmc.uu.se>:
> Ryogo Sugitani wrote:
> > David,
> >
> > How about adding [ nonbond_params ] in your ff???nb.itp file
> > as shown in p.88 of the user's manual?
> > I believe it will override the default vdw interaction for that
> > particular atom-type pair.
> > (Assuming you want to use combination rule #1 just for that atom-type pair)
> >
> > If I miss your point, please disregard this...
> >
> >
> In gromacs 3.3 it will still use the same combination rule. However, in
> older versions, possibly 3.2.1, this would work: use sig/eps for
> generating a matrix and overriding it with C6/C12. We took that out
> because it is hard to explain, and we thought it was unnecessary...
>
> --
> David.


Can we still override just parameters (not the combination rule) in ver 3.3.1?
I was going to use this feature for my calculation in near future, so
I'm a little bit concerned.