Ab Initio Quantum Chemistry Computer Programs

It is, of course, impossible to do ab initio calculations on paper for anything except perhaps the hydrogen atom, and even then extremely time consuming were one to perform many calculations needed to plot a potential energy curve, especially considering that most ab intio methods are iterative (SCF) methods. For this reason, computers are naturally employed. Computer software for performing quantum calculations are typically run on supercomputers or clustered networks used to create a ‘distributed supercomputer’, but are increasingly run on workstations and even common x86 desktops, such is the increased power of personal computers available today. Of course, only the supercomputers can handle large calculations and even then may take several days.
This section lists some of the currently available software.

Gaussian

Gaussian is a popular ab initio program available as the latest version, Gaussian 98, for supercomputers, workstations and PCs running UNIX, Linux, Microsoft Windows and MacOS X operating systems.
Gaussian can do most ab initio methods, such as Hartree-Fock, MCSCF, CI and DFT, including perturbation corrections to Hartree-Fock such as MP2, MP3, MP4 and CC.
A literature survey in 1993 found that Gaussian was the most widely used quantum chemistry program at the time.

GAMESS

GAMESS (General Atomic and Molecular Electronic Structure System) is a free ab initio program, also available for UNIX, Linux, MacOS (7.9 and OS X) and Microsoft Windows. GAMESS was reportedly the second-most used ab initio quantum chemistry program in 1993, and can do HF, MCSCF and CI calculations, with some perturbation corrections (MP2).

MOLPRO

MOLPRO is an ab initio program originally designed by H.-J. Werner and P.J. Knowles (See also: MRCI; section 8.1 and references 24–26) at the University of Birmingham. It is available for UNIX and Linux workstations and supercomputers and is designed for accurate calculations on small molecules, using MCSCF (CASSCF) and MRCI methods. It also supports DFT methods.

HyperChem

HyperCube’s HyperChem is a computational chemistry package that, amongst other things, can do ab initio calculations at the Hartree-Fock and DFT levels, including some semi-empirical methods.
HyperChem is available for Windows PCs and workstations, and also, interestingly, for PocketPC (Windows CE) handheld devices!