title: A Gaussian wave packet phase-space representation of quantum canonical statistics.
abstract: 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.affiliation: School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom.
authors.forename: David J
authors.initials: DJ
authors.lastname: Coughtrie
authors.affiliation: School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom.
authors.forename: David P
authors.initials: DP
authors.lastname: Tew