Breathing-mode lattice relaxation associated with the vacancy and phosphorus-vacancy-pair ( E -center) defect in silicon

Comparison of published theoretical results on the lattice volume (breathing-mode) relaxation associated with the formation of the vacancy in silicon with the experimentally determined relaxation associated with the closely related phosphorus-vacancy-pair (or E-center) defect is used to provide a badly needed calibration on both the theoretical and experimental methods and leads to definitive conclusions about the sign (outward) and magnitude ({}5% of the Si-Si bond length) of this relaxation for the neutral charge states of both defects. The charge-state dependence of this relaxation is also discussed.