New Classical Models for Silicon Structural Energies.

A theory of classical two and three body interatomic potentials is developed. The ability of the classical potentials to model quantum mechanical local density functional calculations for a wide range of silicon structures is explored. In developing classical models it was found to be necessary to perform new local density functional calculations for self-interstitial structures. One potential models bulk energies and high pressure properties well; the other is more appropriate for properties of the tetrahedral structure. Simulated annealing is used to find low energy structures for silicon atom-clusters.