title: Thermodynamic integration from classical to quantum mechanics.
abstract: We present a new method for calculating quantum mechanical corrections to classical free energies, based on thermodynamic integration from classical to quantum mechanics. In contrast to previous methods, our method is numerically stable even in the presence of strong quantum delocalization. We first illustrate the method and its relationship to a well-established method with an analysis of a one-dimensional harmonic oscillator. We then show that our method can be used to calculate the quantum mechanical contributions to the free energies of ice and water for a flexible water model, a problem for which the established method is unstable.
authors.affiliation: Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom. scott.habershon@bristol.ac.uk
authors.forename: Scott
authors.initials: S
authors.lastname: Habershon
authors.forename: David E
authors.initials: DE
authors.lastname: Manolopoulos