**Please note: The FAQ pages at the HPCVL website are continuously being revised. Some pages might pertain to an older configuration of the system. Please let us know if you encounter problems or inaccuracies, and we will correct the entries.**

The "General Atomic and Molecular Electronic Structure System" (GAMESS) is a quantum chemistry software package that was assembled from various older codes (in particular, HONDO) by M. Dupuis, D. Spangler, and J. J. Wendoloski of the National Resources for Computations in Chemistry (NRCC). The code has undergone great changes since then and is maintained now by the Gordon Research Group at Iowa State University.

Gamess performs a great many of standard quantum chemical calculations. These include:

- RHF, UHF, ROHF, GVB, or MCSCF self-consistent calculations.
- CI or MP2 corrections to the energy.
- Semi-empirical MNDO, AM1, or PM3 methods.
- Analytic energy gradients for SCF, MP2 or CI.
- Geometry optimizations, saddle point searches, and vibrational frequencies.
- Intrinsic reaction paths, gradient extremal curves, and dynmic reaction coordinates.
- Many molecular properties, such as densities, electrostatic potentials, dipole moments, etc.
- Modelling of solvent effects and electric fields.

For a complete list of capabilities of GAMESS, consult this table or download the Gamess documentation.

The present version of Gamess is described in *General Atomic and Molecular Electronic Structure System*; M.W.Schmidt, K.K.Baldridge, J.A.Boatz, S.T.Elbert, M.S.Gordon, J.H.Jensen, S.Koseki, N.Matsunaga, K.A.Nguyen, S.Su, T.L.Windus, M.Dupuis, J.A.Montgomery; *J. Comput. Chem.* **14**, 1347-1363 (1993) and *Advances in electronic structure theory: GAMESS a decade later*; M.S.Gordon, M.W.Schmidt *pp. 1167-1189* in *Theory and Applications of Computational Chemistry: the first forty years*; C.E.Dykstra, G.Frenking, K.S.Kim, G.E.Scuseria (editors), Elsevier, Amsterdam, 2005.