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453. MERCURY: A General Monte Carlo Classical Trajectory
Program
by William L. Hase, Department of Chemistry, Wayne State University, Detroit, Michigan 48202 This computer program will perform five different types of calculations, as specified by the parameter NSELT: NSELT = -1 Perform a normal mode analysis at a geometry which is read in. NSELT = 0 Calculate a trajectory from coordinates and momenta which are read in. NSELT = 1 Determine the equilibrium geometry for a specified potential energy surface. NSELT = 2 Calculate a trajectory for one reaction. NSELT = 3 Calculate a trajectory for a collision between two reactants. For NSELT = 2 and 3, the initial conditions may be chosen for three different types of excitation, as specified by the parameter NACT: NACT = 1 Choose reactant initial conditions with orthant sampling. NACT = 2 Choose reactant initial conditions with microcanonical normal mode sampling. NACT = 3 Choose reactant initial conditions with fixed normal mode energies. For a diatomic reactant, the normal mode may be either a harmonic or Morse oscillator. The methodology of classical trajectory calculations for triatomic systems has been reviewed on several occasions.1-4 Descriptions of trajectory methods for polyatomics are limited5, so a rather detailed summary of the techniques used in this program is outlined in the documentation.Integration of the classical equations of motion is standard in that combined fourth-order Runge-Kutta and sixth-order Adams-Moulton Algorithms are used.1,6 _________ References: 1. D. L. Bunker, Meth. Comput. Phys., 10, 287 (1971). 2. R. N. Porter and L. M. Raff, in Dynamics of Molecular Collisions, Part B, ed. W. H. Miller (New York: Plenum, 1976), p. 1. 3. M. D. Pattengill, in Atom-Molecule Collision Theory, ed. R. B. Bernstein (New York: Plenum, 1979), p. 359. 4. D. G. Truhlar and J. T. Muckerman, ibid., p. 505. 5. W. L. Hase, in Aspects of the Kinetics and Dynamics of Surface Reactions, AIP Conference Proceedings, No., 61, ed. U. Landman, AIP, New York, 1980, p. 109. 6. C. A. Parr, Ph.D. thesis, California Institute of Technology. _________ FORTRAN IV (Amdahl/IBM) Lines of Code: 4340 |