Re: [AMBER] What's the combine rules for OPLS force field in AMBER?

From: case <>
Date: Thu, 15 Dec 2011 22:43:02 -0500

On Thu, Dec 15, 2011, Guoxiong Su wrote:
> I am wondering what the combine rules for OPLS force field is in
> AMBER. Because in OPLS force field, epsilon and r are both geometric
> mean of the two input values.

You can use the "AC" option to the nonbonded parameter list to turn on the
mixing rules that OPLS uses. Note (a) the parameters are the coefficients
of the r**-12 and r**-6 terms, not r and epslion (see opls_parm.dat for a
very old example); (b) you should certainly carefully test the resulting
prmtop file for simple examples, since this option is rarely used or


AMBER mailing list
Received on Thu Dec 15 2011 - 20:00:02 PST
Custom Search