Subject: Re: CCL:Monte Carlo,again...

From: [email-masked] (Graham Hurst)
Date: Thu, 9 Jun 1994 17:28:32 -0400

Phil Xiang <[email-masked]> asks:
> Let me be more specific. I want to use Monte Carlo method to sample the 
> conformational space of a small drug molecule to find the global and local
> minima. The molecular mechanics programs I have are AMBER and CHARMM, none of
> which came with Monte Carlo utility.

The combination of HyperChem and ChemPlus can be used for Monte Carlo
conformational searches for low energy conformations, using MM+ (extension
of MM2), AMBER, CHARMM, or OPLSA molecular mechanics force fields or CNDO,
INDO, INDO/1, INDO/S, MINDO/3, MNDO, AM1 or PM3 semi-empirical quantum
mechanics to define the potential surface.  For rings it uses the TFLEX
algorithm of Istvan Kolosovary and Wayne Guida, and has no software
limitations on the number of torsions that can be varied.  There are
several options for search methodology and testing for duplication of 
conformations (including automatically determining equivalent atom
orderings).

They are both commercial products (academic prices for HyperChem and ChemPlus
are US$ 995 and US$ 495 respectively) that run on PCs with Windows, and I
have a very vested interest - I wrote the conformational search module in
ChemPlus and have been a HyperChem developer since '88!  To get more info,
send email to [email-masked].

In the DOS/Windows world there are two other programs I can think of that
might fulfill your need.  One that has been advertised recently is
PowerSearch by Tripos, which uses the Tripos force field and I don't think
that it can handle rings.  I think that PC Model by Serena can also do
Monte Carlo conformational searches, using their MMX force field.

Hope this helps,

Graham Hurst
------------
Graham Hurst
Hypercube Inc, 7-419 Phillip St, Waterloo, Ont, Canada N2L 3X2 (519)725-4040
internet: [email-masked]