From owner-chemistry@ccl.net Thu Oct 13 20:26:00 2005 From: "Mark Thompson mark]~[arguslab.com" To: CCL Subject: CCL: partial charge fitting - free QM package Message-Id: <-29600-051013191114-19095-mMhCc7zLGCfLZ0QczuOQMA###server.ccl.net> X-Original-From: Mark Thompson Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1; format=flowed Date: Thu, 13 Oct 2005 16:11:01 -0700 MIME-Version: 1.0 Sent to CCL by: Mark Thompson [mark.|.arguslab.com] > I am constructing drug molecules to dock into a receptor using > molecular mechanics forcefield representation of atoms. The drug > molecules were built in Sybyl and partial charges were first added > using the Gasteiger-Marsili charges by default. I then performed an > AM1 MOPAC calculation to derive Mulliken charges which were differed > to some extent. I do not currently have a program to perform higher > level ab initio calculations from which tto derive better charges. > > Where may I obtain a free QM program that performs ab initio > calculations with acceptable basis sets for small organic molecules > from which to derive MM partial charges? GAMESS is a good program. It's free. (http://www.msg.ameslab.gov/GAMESS/GAMESS.html) Mark ---------------------------- Mark Thompson mark|arguslab.com http://www.arguslab.com ----------------------------