The formation, migration, and activation volumes for mono-vacancies under zero or finite external pressures were calculated from first principles within the framework of the local-density approximation and pseudopotential method. In both metals, the activation volumes were smaller than half of the atomic volume. The approximations which were involved, in the transition-state theory that was the basis of the calculations, were considered with particular regard to the limitations of the theory at very high pressures.

U.Breier, V.Schott, M.Fähnle: Physical Review B, 1997, 55[9], 5772-7