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557. TSTPST: Statistical Theory Package for
RRKM/QET/TST/PST Calculations
by Walter J. Chesnavich, Lew Bass, M. Edward Grice, Kihyung Song and Douglas A. Webb, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409 TSTPST is a collection of subroutines and functions used to calculate sums and densities of states for RRKM/QET/TST/PST calculations. TSTPST contains subroutines for tight (traditional) transition states, for orbiting (phase space theory) transition states, and for unimolecular reagents, fragments, etc. The sums and densities are calculated using the Beyer- Swinehart algorithm, with vibrational degrees of freedom treated as harmonic oscillators and rotational degrees of freedom as rigid rotors. The orbiting transition state subroutines are designed to handle both ion-molecule and neutral-neutral reactions. However, the subroutines are programmed only for the spherical long-range potentials -cr-4 and -cr-6. Also, the approximations of Klots and of Chesnavich and co-workers are used for linear molecules. The complete TSTPST package consists of all of the subroutines and functions needed to calculate sums and densities of states, a number of main programs to demonstrate how the package is used, and a set of Gauss-Legendre points and weights for use in numerical integrations. Two of the main programs demonstrate how to use TSTPST to calculate a unimolecular rate constant and a phase space theory cross section. The third demonstrates how TSTPST can be applied to more complex systems by using as a model a biomolecular reaction in which one of the products can decompose to give a secondary product. TSTPST was written to conform to standard ANSI FORTRAN 77 and, as such, can be expected to run properly only on true FORTRAN 77 compilers. The package has been successfully tested on VAX 11/780 and 8650 mainframe computers using the VAX FORTRAN Version 4.3 compiler and on Macintosh Plus, SE and II personal computers using the Absoft MacFortran Version 2.3 compiler. If you either successfully run (or fail to run) the package on another computer, please let us know. FORTRAN 77 Lines of Code: 1172 |