GAMESSPLUSRATE 9.3

Abstract: GAMESSPLUSRATE is a set of FORTRAN 77 subroutines and Unix shell scripts for interfacing the POLYRATE and GAMESSPLUS computer programs for the purpose of carrying out direct dynamics calculations of gas-phase and liquid-phase chemical reaction rates of polyatomic species (and also atoms and diatoms as special cases) using the electronic structure methods available in GAMESSPLUS to calculate the potential energy surface and POLYRATE for the dynamics. The interface is based on the POLYRATE hooks protocol. The dynamical methods used are variational or conventional transition state theory and multidimensional semiclassical approximations by any of the POLYRATE methods for tunneling and nonclassical reflection. Gas-phase rate constants may be calculated by any of the methods available in the POLYRATE-version 8.5 program for canonical or microcanonical ensembles or for specific vibrational states of selected modes with translational, rotational, and other vibrational modes treated thermally. Liquid-phase rate constants may be calculated by the separable equilibrium solvation (SES), equilibrium solvation path (ESP) approximation, or nonequilibrium solvation (NES) approximation. Bimolecular and unimolecular reactions are included. Both single-level and dual-level methods for dynamics calculation are available. In single-level mode, optimized geometries, potential energies, gradients, and Hessians can be calculated by any of the size-consistent ab initio or semiempirical methods in the GAMESSPLUS GAMESSPLUS package. In dual-level mode, the lower-level data is calculated by GAMESSPLUS, and the higher-level data is read from an external file. In addition, the liquid-solution reaction rate constants can be calculated using separable equilibrium solvation (SES), equilibrium solvation path (ESP), or nonequilibrium solvation (NES) approximations. GAMESSPLUSRATE also includes a linear coefficient method for mixing two electronic structure theories, and this capability may be used, for example, to carry out calculations by the linear combination of Hartree-Fock and Molecular Orbital Theory (HF||MO) approximation. The GAMESSPLUSRATE interface of GAMESSPLUS with POLYRATE is similar to the GAUSSRATE interface of GAUSSIAN with POLYRATE; however only GAMESSPLUSRATE contains the linear coefficient capability.

The user needs to obtain all three of the following packages:

From the University of Minnesota:

• GAMESSPLUSRATE: GAMESSPLUSRATE is a licensed code available from the Univer sity of Minnesota. Currently the license fee is waived for all users. For further information about GAMESSPLUSRATE code see http://comp.chem.umn.edu/gamessplusrate.
• POLYRATE: POLYRATE is a licensed code available from the University of Minnesota. Currently the license fee is waived for all users. For further information about POLYRATE see http://comp.chem.umn.edu/polyrate.
• GAMESSPLUS: GAMESSPLUS is a licensed code available from the University of Minnesota. Currently the license fee is waived for all users. For further information about GAMESSPLUS see httpd://comp.chem.umn.edu/gamessplus.

• GAMESS: GAMESS is a licensed code available from the Gordon research group at Iowa State University. For further information see http://www.msg.ameslab.gov/GAMESS/GAMESS.html.