Molecular-dynamics study of the melting of hexagonal and square lattices in two dimensions

Simple pair potentials are discussed which give hexagonal- and square-lattice ground states in two dimensions. Molecular-dynamics calculations for these potentials are used to study transitions between the two lattices and melting. The melting temperature is found to be a minimum near the point where the barrier between the two structures, as a function of lattice strain, is also a minimum.