Zero-point energy correction for trajectory rate data

Abstract

Classical trajectory simulations are often used to calculate rate coefficients and other dynamical properties. Such calculations have a systemic error arising from leakage of zero-point energy into the reaction coordinate. Shen and Pritchard (J. Chem. Soc., Faraday Trans., 1996, 92, 4357) have recently proposed a method to correct the rate coefficient. This paper shows that the Shen–Pritchard correction factor is applicable to ergodic systems and can be derived from transition-state theory. The relationship to the quantum-mechanical threshold method of Varandas and co-workers is shown and the implications for rate and product-distribution calculations are discussed.

References

1. R. N. Porter and L. M. Raff, in Dynamics of Molecular Collisions, ed. W. H. Miller, Plenum Press, New York, 1976, vol. B, p. 1; J. I. Steinfeld, J. S. Francisco and W. L. Hase, Chemical Kinetics and Dynamics, Prentice Hall, Englewood Cliffs, NJ, 1989; J. N. Murrell and S. D. Bosanac, Introduction to the Theory of Atomic and Molecular Collisions, Wiley, Chichester, 1989.
2. R. G. Gilbert and S. C. Smith, Theory of Unimolecular and Recombination Reactions, Blackwells Scientiffc, Oxford, 1990.
3. K. F. Lim and J. I. Brauman, J. Chem. Phys., 1991, 94, 7164 and references therein.
4. L. L. Gibson, G. C. Schatz, M. A. Ratner and M. J. Davis, J. Chem. Phys., 1987, 86, 3263.
5. J. Davidsson and G. Nyman, J. Chem. Phys., 1990, 92, 2407.
6. A. J. C. Varandas and J. M. C. Marques, J. Chem. Phys., 1994, 100, 1908 and references therein.
7. D. L. Shen and H. O. Pritchard, J. Chem. Soc., Faraday Trans., 1996, 92, 4357.
8. J. M. Bowman, B. Gazdy and Q. Sun, J. Chem. Phys., 1989, 91, 2859; W. H. Miller, W. L. Hase and C. L. Darling, J. Chem. Phys., 1989, 91, 2863.
9. G. H. Peslherbe and W. L. Hase, J. Chem. Phys., 1994, 100, 1179; 1996, 104, 9445.
10. M. Ben-Nun and R. D. Levine, J. Chem. Phys., 1994, 101, 8768.
11. (a) K. F. Lim and D. A. McCormack, J. Chem. Phys., 1995, 102, 1705; (b) D. A. McCormack and K. F. Lim, J. Chem. Phys., 1995, 103, 1991; (c) 1997, in the press.
12. D. A. McCormack and K. F. Lim, in preparation.
13. F. E. Budenholzer, M. Y. Chang and K. C. Huang, J. Phys. Chem., 1994, 98, 12501.