CHARMM (Chemistry at HARvard Macromolecular Mechanics) is a program for macromolecular dynamics and mechanics. It performs standard molecular dynamics in many different ensembles (e.g., NVE, NVT, NPT) using state-of-the-art algorithms for timestepping, long range force calculation and periodic images. CHARMM can be used for energy minimization, normal modes and crystal optimizations as well. The potential energy functions available for use with CHARMM have been extensively parameterized for simulations of proteins, nucleic acids and lipids. Free energy methods for chemical and conformational free energy calculations are also fully developed and available in CHARMM. Many other novel tools have been developed and are available in CHARMM, these include: replicas (multiple copies); many types of restraints and constraints, including fixed atoms, atomic, NOE, dihedral and internal coordinate restraints and generalized SHAKE for bonds and arbitrary internal coordinates; minimium energy path following and transition state optimization; etc.

CHARMM development began in the research group of Professor Martin Karplus at Harvard University. Development continues throughout the world with contributing developers in over 20 universities, research institutes and companies. CHARMM is available to academic users in full source form, plus extensive documentation and test input scripts, through Harvard University. A license for CHARMM can be obtained by inquiring to:

Professor Martin Karplus
Department of Chemistry & Chemical Biology
Harvard University
12 Oxford Street
Cambridge, MA 02138
Email:

The appropriate references for CHARMM in publications are:

CHARMM: A Program for Macromolecular Energy, Minimization, and Dynamics
Calculations, J. Comp. Chem. 4, 187-217 (1983), by B. R.
Brooks, R. E. Bruccoleri, B. D. Olafson, D. J. States, S. Swaminathan,
and M. Karplus.

CHARMM: The Energy Function and Its Parameterization with an Overview
of the Program, in The Encyclopedia of Computational Chemistry, 1,
271-277, P. v. R. Schleyer et al., editors (John Wiley & Sons: Chichester,
1998), by A. D. MacKerell, Jr., B. Brooks, C. L. Brooks, III, L. Nilsson,
B. Roux, Y. Won, and M. Karplus. 

CHARMM (the commercial version of CHARMM) is available to scientists
in industry, and academic researchers who wish to have full user support,
through Accelrys