Using a mixed basis pseudopotential method, total energy calculations were performed to obtain the enthalpy of vacancy formation in Ta as a function of pressure, which was important for understanding the effects of pressure on mechanical properties. The vacancy formation enthalpy was found to increase from 2.95eV at ambient pressures to 12.86eV at 300GPa, and the vacancy formation volume decreased from being 53% of the bulk volume per atom at ambient pressure to 20% at 300GPa, for a 54-atom super-cell. It was also shown that there was a strong correspondence between the vacancy formation enthalpy and the melting point in Ta.

Vacancy Formation Enthalpy at High Pressures in Tantalum. S.Mukherjee, R.E.Cohen, O.Gülseren: Journal of Physics - Condensed Matter, 2003, 15[6], 855-61