Stable Long-Time Semiclassical Description of Zero-Point Energy in High-Dimensional Molecular Systems

Sophya V. Garashchuk, University of South Carolina - Columbia
V. A. Rassolov

Copyright 2008 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

The following article appeared in

Garashchuk, S. & Rassolov, V. A. (2008). Stable long-time semiclassical description of zero-point energy in high-dimensional molecular systems. The Journal of Chemical Physics, 129, 024109. http://dx.doi.org/10.1063/1.2949095

and may be found at

http://scitation.aip.org/content/aip/journal/jcp/129/2/10.1063/1.2949095

Abstract

Semiclassical implementation of the quantum trajectory formalism [J. Chem. Phys.120, 1181 (2004)] is further developed to give a stable long-time description of zero-point energy in anharmonic systems of high dimensionality. The method is based on a numerically cheap linearized quantum force approach; stabilizing terms compensating for the linearization errors are added into the time-evolution equations for the classical and nonclassical components of the momentum operator. The wave function normalization and energy are rigorously conserved. Numerical tests are performed for model systems of up to 40 degrees of freedom.