[gmx-users] parameters for Cerium

[Lieven Buts]

Elena Molteni wrote:
> 2) anyway, how can I obtain reasonably good VdW "c6" and "c12" parameters
> for Ce(III)? (without running an ab initio calculation or something like
> that!) Which is their exact definition? (I know the general form of the VdW
> potential, but I remember there are slightly different definitions...). Can
> I find some information on this on the gromacs website or somewhere else?

Last year I converted the Lennard-Jones parameters for manganese(2+)
ions
from the MM3 force field to something Gromacs could use. My conversion
is available in the gmx-users archive:

http://www.gromacs.org/pipermail/gmx-users/2002-March/027624.html

along with a verification I did on calcium(2+) ions:

http://www.gromacs.org/pipermail/gmx-users/2002-April/027957.html
http://www.gromacs.org/pipermail/gmx-users/2002-April/027968.html
http://ultr.vub.ac.be/~lieven/test.png

I have used these parameters in a protein simulation. I do not think
they are very critical in this context, and the structure of the metal
binding site is stable throughout the simulation and matches everything
I read about it. 

If you could find similar parameters for Ce(III), maybe you could
do an analogous conversion.

-- 
Lieven Buts
Department of Ultrastructure
Vrije Universiteit Brussel