Q. What is GAMESS-US?

A. GAMESS-US (General Atomic and Molecular Electronic Structure System - US version) is an ab initio quantum chemistry software package that is widely used for computational chemistry research.
It is designed to perform a variety of electronic structure calculations, including Hartree-Fock, density functional theory (DFT), and post-Hartree-Fock methods such as MP2, coupled-cluster, and configuration interaction. GAMESS-US is capable of handling both ground and excited states of molecules and provides tools for analyzing chemical reactions, molecular properties, and spectra.