GAMESS – ab initio molecular electronic structure software

The General Atomic and Molecular Electronic Structure System (GAMESS) is a general ab initio quantum chemistry package.

GAMESS can compute SCF wavefunctions ranging from RHF, ROHF, UHF, GVB, and MCSCF. Correlation corrections to these SCF wavefunctions include Configuration Interaction, second order perturbation Theory, and Coupled-Cluster approaches, as well as the Density Functional Theory approximation.

Nuclear gradients are available, for automatic geometry optimization, transition state searches, or reaction path following. Computation of the energy hessian permits prediction of vibrational frequencies, with IR or Raman intensities. Solvent effects may be modeled by the discrete Effective Fragment potentials, or continuum models such as the polarizable Continuum Model.

Numerous relativistic computations are available, including third order Douglas-Kroll scalar corrections, and various spin-orbit coupling options. The Fragment Molecular Orbital method permits use of many of these sophisticated treatments to be used on very large systems, by dividing the computation into small fragments. Nuclear wavefunctions can also be computed, in VSCF, or with explicit treatment of nuclear orbitals by the NEO code.

The original code split in 1981 into GAMESS (US) and GAMESS (UK) variants, which now differ significantly.

GAMESS-UK’s features include:

• Performs a number of general computational chemistry calculations, including Hartree-Fock, Density functional theory (DFT),
  Generalized Valence Bond (GVB), and Multi-configurational self-consistent field (MCSCF).
• Correlation corrections after these SCF calculations can be estimated by configuration interaction (CI), second order Møller-Plesset perturbation theory, and coupled cluster theory.
• Solvent effect can be considered using discrete effective fragment potentials or continuum models (such as PCM). Relativistic
  corrections can be calculated, including third order Douglas-Kroll scalar terms.
• Can be interfaced with the TINKER code for molecular mechanics to do mixed molecular mechanics/quantum mechanics calculations.
• The Fragment Molecular Orbital method can be used to treat large systems, by dividing them into fragments.
• Can also be interfaced with the valence bond VB2000 and XMVB programs and the Natural Bond Orbital (NBO) population analysis program.

GAMESS-UK’s features include:

• Hartree Fock:
  • Segmented, generally contracted and harmonic basis sets.
  • SCF-Energies: conventional and in-core.
  • SCF-Gradients: conventional and in-core.
  • SCF-Frequencies: numerical and analytical 2nd derivatives.
  • Parallelized conventional SCF.
  • Restricted and unrestricted open shell SCF.
  • Generalized valence bond.
• Density Functional Theory
  • Energies and gradients for closed and open shell systems.
  • A wide variety of exchange, correlation and exchange +
    correlation functionals, including: LYP, B3LYP, BLYP, BP86, BP97, B97, HCTH 93 (120, 147 & 407 ), PBE, Fialtov Thiel ’97, PWG1, B97-1(&2), EDF1 and others.
  • Energy and gradients can be evaluated for Meta-GGA functionals, including BB95, B1B95 and BB1K.
  • Optimised Fitted Coulomb Module.
  • Analytic and Numerical 2nd derivatives.
  • Parallelized implementation.
• Electron Correlation:
  • MP2 Frequencies for closed and open shell.
  • MP3 Energies.
  • MCSCF Energies and gradients.
  • CASSCF Energies, gradients and numerical 2nd derivatives.
  • MR-DCI Energies, properties and transition moments.
  • CCSD and CCSD(T) Energies.
  • RPA (direct) and MCLR excitation energies and oscillator strengths.
  • Full-CI Energies.
  • Green’s functions calculations of Ionization Potentials.
• Capabilities:
  • Direct-SCF and -DFT Energies, analytical gradients, and numerical
    2nd derivatives.
  • Direct-MP2 Energies, analytical gradients, and numerical 2nd derivatives.
  • Direct-RPA computation of excitation energies.
  • Semi-direct MRDCI energies.
  • Parallelized direct-SCF and direct-MP2 gradients, direct-SCF frequencies, and direct-RPA.
• Molecular Properties:
  • Mulliken and Lowdin population analysis.
  • Electrostatic Potential-Derived Charges.
  • Distributed Multipole Analysis.
  • Morokuma Analysis.
  • Natural Bond Orbital (NBO) Analysis.
  • Interface to Bader’s AIMPAC code.
  • IR and Raman Intensities.
  • Multipole Moments.
  • Polarizabilities, Hyperpolarizabilities and Magnetizabilities.
  • Relativistic Effects (ZORA).
  • Solvation Effects (DRF).
• Pseudopotentials:
  • Local and non-local pseudopotentials, with the ability to calculate the second derivatives of the energy.
• Hybrid QM + MM:.
  • Interface to Charmm.
  • Interface to ChemShell.
• Semi-empirical:
  • MNDO, AM1, and PM3 hamiltonians.
• Visualisation:
  • Pre- and post-processing.
  • View both scalar and vector data with the CCP1GUI.

Website: www.msg.chem.iastate.edu/gamess
Support:
Developer: CFS
License: GAMESS-UK Licenses

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