Introduction

What is CHARMM?

CHARMM (Chemistry at HARvard Macromolecular Mechanics) is a computational package used for classical, quantum and hybrid quantum/classical simulations. CHARMM is a complex program with over 500,000 lines of code and offers many analytical features. The program employs a command line interface and in practice most interaction with the program is done via user-created input scripts.

Who developed CHARMM?

CHARMM was created by the Martin Karplus Group at Harvard but developers from across the globe are continually working to improve CHARMM and add new features. A partial list of current CHARMM developers can be found here.

What are some of the features of CHARMM?

• Robust Langevin and molecular dynamics simulation engine

• Extensive trajectory analysis features.

• Much of the code is parallelized for execution on SMP machines and clusters.

• Multiscale modeling (e.g. QM/MM simulations).

• Interfaces to various QM packages.

• Embedded X11 graphics subsystem.

• Facilities for normal mode and quasiharmonic analysis.

• For more information see CHARMM Documentation