Classical Wigner method with an effective quantum force: application to reaction rates

Jens Aage Poulsen; Huaqing Li; Gunnar Nyman

doi:10.1063/1.3167299

Classical Wigner method with an effective quantum force: application to reaction rates

J Chem Phys. 2009 Jul 14;131(2):024117. doi: 10.1063/1.3167299.

Authors

Jens Aage Poulsen¹, Huaqing Li, Gunnar Nyman

Affiliation

¹ Department of Chemistry, Physical Chemistry, University of Gothenburg, SE-412 96 Gothenburg, Sweden. jens72@chem.gu.se

PMID: 19603980
DOI: 10.1063/1.3167299

Abstract

We construct an effective "quantum force" to be used in the classical molecular dynamics part of the classical Wigner method when determining correlation functions. The quantum force is obtained by estimating the most important short time separation of the Feynman paths that enter into the expression for the correlation function. The evaluation of the force is then as easy as classical potential energy evaluations. The ideas are tested on three reaction rate problems. The resulting transmission coefficients are in much better agreement with accurate results than transmission coefficients from the ordinary classical Wigner method.