AMBER Archive (2001)

Subject: L-J mixing rules?

From: Kevin Van Workum (vanw_at_tticluster.com)
Date: Mon Aug 27 2001 - 11:10:24 CDT

Could someone please explain to me how the non-bonded interaction
parameters are determined? Are the usual mixing rules applied? Here's a
piece of param99.dat from the website:

MOD4 RE
OH 1.7210 0.2104 OPLS
CA 1.9080 0.0860 Spellmeyer

So what are the parameters for an OH-CA interaction? Are the following
true:
sigma = (1.721 + 1.9080)/2
epsilon = (0.2104*0.086)^0.5
non-bonded-energy = epsilon/4*[(r/sigma}^12 - (r/sigma)^6]

Kevin Van Workum
www.tsunamictechnologies.com