Replica-exchange Monte Carlo method for the isobaric–isothermal ensemble

We propose an extension of replica-exchange Monte Carlo method for canonical ensemble to isothermal–isobaric ensemble as an effective method to search for stable states quickly and widely in complex configuration space. We investigated the efficiency of the new method on a benchmark testing system which consists of 256 Lennard-Jones particles. The new method enables us to shorten dramatically the relaxation time of phase change from liquid structure to crystal structure in comparison with the conventional Monte Carlo method.