The formation energy and formation volume of monovacancies were calculated to high accuracy by using  ab initio  mixed-basis pseudopotential theory and the local density approximation. This took account of structural relaxation of the atoms around the vacancy in order to judge the reliability of  ab initio  electron theory for the treatment of vacancies in transition metals. The calculated formation energy of 2.9eV was in excellent agreement with experimental data gleaned from positron annihilation. A value of 0.6 of an atomic volume was found for the formation volume.

Ab Initio Calculation of the Formation Energy and the Formation Volume of Monovacancies in Mo B.Meyer, M.Fähnle: Physical Review B, 1997, 56[21], 13595-8