The structure of atomic and molecular clusters, optimised using classical potentials

The problem of the determination of the minimum energy configuration of an arrangement of N point particles under the interaction of their interatomic forces is discussed. The interatomic forces are described by classical many body potentials. Different optimisation methods are considered, multi level single link, topographical differential evolution and a genetic algorithm but it is shown that genetic algorithms combined with an efficient local optimisation method is especially quick and reliable for this task. In addition to comparing some different optimisation methods, the structures of clusters of atoms described by interatomic potential functions containing up to a few hundred atoms are calculated including some with some special symmetries. A number of applications are given including covalent carbon and silicon clusters, close-packed structures such as argon and silver and the two-component carbon–hydrogen system.