Ab initio replica-exchange Monte Carlo method for cluster studies

We have developed an algorithm for replica-exchange Monte Carlo simulations based on an ab initio correlated electronic structure theory. The many-body interactions in metal, semiconductor and molecular clusters are described by an ab initio correlated method at the level of second-order Møller–Plesset perturbation theory. The replica-exchange Monte Carlo procedure allows for an efficient sampling of the global and low-lying local minima in a single simulation run, and thus is ideally suited for locating energy minima of complex systems which possess many local minima. We have successfully applied the replica-exchange Monte Carlo method to the geometry optimization of the Li6 cluster.