GAMESS: General Atomic and Molecular Electronic Structure System

GAMESS is a large computer program written to perform a wide range of quantum chemical computations, such as:

1. Electron densities
2. Electrostatic potentials
3. Electric field and electric field gradients
4. A variety of molecular wavefunctions

GAMESS is one of the many quantum chemistry programs, developed for doing computational chemistry. Other examples are Gaussian92, MOPAC, SYBL, and Discoverer.

To use GAMESS, and input file for the molecule is written by the researcher. Depending on which "parameters" are selected, and output file of varying size is created.