NWChemrate is a set of Fortran subroutines and Unix scripts for interfacing the Polyrate and NWChem computer programs for the purpose of carrying out direct dynamics calculations of chemical reaction rates of polyatomic species (and also atoms and diatoms as special cases) using the electronic structure methods available in NWChem 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 for tunneling and nonclassical reflection. Rate constants may be calculated by any of the methods available in Polyrate for canonical or microcanonical ensembles or for specific vibrational states of selected modes with translational, rotational, and other vibrational modes treated thermally. Bimolecular and unimolecular reactions are included. Both single-level and dual-level calculations may be carried out. In single-level mode, optimized geometries, potential energies, gradients, and Hessians can be calculated by any of the density functionals or coupler cluster methods in the NWChem package or with the MP2 ab initio method. In dual-level mode, the lower-level data is calculated by NWChem, and the higher-level data is read in from an external file.
The user needs to obtain the following packages:
From the University of Minnesota: