LATTICE-RELAXATION AT VACANCY AGGREGATES IN DIAMOND

Lattice relaxation about a vacancy and small vacancy aggregates is mod eled using a damped molecular dynamics procedure, the lattice potentia l taking Stillinger-Weber form. Relaxation about a single vacancy is f ound to be relatively small and this is used as a quantitative measure of the extent of relaxation characterizing various vacancy aggregates . Relaxation is important in deciding the preferential orientation of vacancy aggregates in the crystal, with aggregation involving vacancie s on near neighbor lattice sites being less favored. The formation ene rgies deduced for vacancy aggregation start at similar to 30 eV.