Free energy evaluation in the canonical molecular dynamics ensemble

Abstract

A new method for evaluating free energy differences between thermodynamic states of a given system at different temperatures is proposed. The method is based on the study of the fluctuations of the mass scaling parametet that enters the newly developed canonical molecular dynamics method of Nosé [1]. The method is numerically tested in the calculation of the free energy of a 13-atoms Lennard-Jones cluster. In this case the method is computationally more effective then conventional methods and offers the possibility of checking the internal consistency of the results.