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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
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