skip to main content

Title: A Gaussian wave packet phase-space representation of quantum canonical statistics

We present a mapping of quantum canonical statistical averages onto a phase-space average over thawed Gaussian wave-packet (GWP) parameters, which is exact for harmonic systems at all temperatures. The mapping invokes an effective potential surface, experienced by the wave packets, and a temperature-dependent phase-space integrand, to correctly transition from the GWP average at low temperature to classical statistics at high temperature. Numerical tests on weakly and strongly anharmonic model systems demonstrate that thermal averages of the system energy and geometric properties are accurate to within 1% of the exact quantum values at all temperatures.
Authors:
;  [1]
  1. School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom)
Publication Date:
OSTI Identifier:
22493441
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; GAUSS FUNCTION; MAPPING; PHASE SPACE; POTENTIALS; QUANTUM MECHANICS; STATISTICS; SURFACES; TEMPERATURE DEPENDENCE; WAVE PACKETS