Generalization of the linearized approximation to the semiclassical initial value representation for reactive flux correlation functions

Journal Article · Thu Nov 25 04:00:00 EST 1999 · Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory

DOI:https://doi.org/10.1021/jp9915275· OSTI ID:20013051

Miller, W H

The semiclassical (SC) initial value representation (IVR) provides a general and practical approach for including quantum effects in classical molecular dynamics simulations. The linearized approximation (LA) to the SC-IVR simplifies the description much further, reducing it to the well-known classical Wigner model (i.e., a classical trajectory calculation with a Wigner distribution of initial conditions); the LA is able to describe quantum effects well for short times (t {approx{underscore}lt} {Dirac{underscore}h}{beta}) but not so for longer times. It is shown here how the full SC-IVR approach, which is able to describe quantum effects for long times, can be cast in a form very similar in structure to the LA, with specific application to flux correlation functions relevant to chemical reaction rates. This formulation may thus make it possible to carry out full SC-IVR calculations while still retaining much of the simplifying aspects of its linearized approximation.

• Research Organization: Univ. of California, Berkeley, CA (US); Lawrence Berkeley National Lab., CA (US)
• Sponsoring Organization: US Department of Energy; National Science Foundation
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 20013051
• Journal Information: Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory, Journal Name: Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory Journal Issue: 47 Vol. 103; ISSN 1089-5639; ISSN JPCAFH
• Country of Publication: United States
• Language: English

Related Subjects

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JACOBIAN FUNCTION
MOLECULAR DYNAMICS METHOD
QUANTUM MECHANICS
SEMICLASSICAL APPROXIMATION