Potential energy functions for atomic solids

A potential energy function has been proposed for atomic solids consisting of two-body and three-body terms which over its range of parameters encompasses all simple crystal structures. Phase diagrams have been constructed as a function of a single parameter in the two-body term and one, of several, parameters in the three-body term, and these include as the most stable structures hcp, fcc, bcc, sc and diamond. The hcp and fcc lattices have been shown to distort to lower symmetries with appropriate three-body parameters and these distortions are in accord with known structures. A brief study has been made of the appropriate parameters for silicon.