Monte-Carlo Simulations in Adiabatic Ensembles

Abstract

We discuss simulations using a recently derived Monte Carlo method which can be modified for use with any of the adiabatic ensembles. As a concrete example we present the first results from simulations using the new Monte Carlo method to generate the HtN ensemble, where H is the enthalpy, and t the thermodynamic tension. This method is the Monte Carlo counterpart of the Parrinello-Rahman form of molecular dynamics. In particular we discuss HtN Monte Carlo calculations of the elastic constants and other related thermodynamic properties of a system from fluctuation formulas specific to the HtN ensemble. The agreement of the results with earlier calculations using other ensembles supports the inference that our Monte Carlo procedure generates the HtN ensemble.