[gmx-users] New LJ parameters for CH2/3-OW

[David van der Spoel]

On Mon, 8 Apr 2002, Pedro Alexandre de Araujo Gomes Lapido Loureiro wrote:

>I want to use the LJ parameters for CH2/3-OW interaction of van Buuren et al (J.
>Phys. Chem. 97, 9206 - 1993).
>I have created a new ff*.* forcefield to edit the values.
>My questions are: in the ff*nb.itp file ...
>1) ... do I have to edit the [atomtypes] field ?
>2) ... do I have to edit the [nonbond_params] field ?
>3) ... does it suffice to edit the [ pairtypes ] field ?

Actually, very similar parameters are already in the ffgmx force field, it
is basically gromos87 + this correction + hydrogens on aromatic groups.

Otherwise the gromos96 forcefield contains a similar patch.

Otherwise for lipid like molecules check out Peter Tielemans parameters
(see link on www.gromacs.org)

Otherwise you can edit either the atomtypes (and make sure the CH2/3-OW
interaction is not in the nonbondtypes), or edit the nonbonded types.
Not that for alkane chains you want the ryckaert bellemans dihedrals.

Groeten, David.
________________________________________________________________________
Dr. David van der Spoel, 	Biomedical center, Dept. of Biochemistry
Husargatan 3, Box 576,  	75123 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://zorn.bmc.uu.se/~spoel
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