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This page was originally developed by Kenno Vanommeslaeghe here.

MacKerell Lab
Computer-Aided Drug Design Center

University of Maryland, Baltimore
Baltimore, MD 21201

CGenFF logo Welcome to the CHARMM General Force Field for organic molecules. If you want to perform simulations on a system that contains a small organic molecule using the CHARMM force field, you've come to the right place. The CGenFF program will provide you with parameters for your specific molecule, which you can read into your simulation software together with the main CGenFF topology and parameter files and parts or all of the CHARMM36 biomolecular force field. Before starting the simulation, please take a moment to examine the penalty scores in the output of the CGenFF program. If they are large, chances are that you'll need to re-optimize the parameters. How to do so is described in K. Vanommeslaeghe et al., J. Comput. Chem. 2010, 31, 671-690 and illustrated by means of two tutorials that can be downloaded from the download page. The procedure is made easier by the lsfitpar program for robust fitting of bonded parameters. Below are some more links and notes.

Usage information for the CGenFF program for automatic atom typing and assignment of parameters and charges by analogy

[K. Vanommeslaeghe et al., J. Chem. Inf. Model. 2012, 52, 3144-3154; K. Vanommeslaeghe et al., J. Chem. Inf. Model. 2012, 52, 3155-3168]

Frequently Asked questions

Download page (includes the CGenFF tutorials)

Important notes - read this before using CGenFF:

This material is based upon work supported by the National Science Foundation under Grant No. 0823198. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Last updated Sunday, the 31st of May 2015