The electronic structure of the neutral and singly charged Mg vacancy in MgO was investigated using density functional theory. For both defects, semi-local exchange correlation functionals such as the local spin density approximation incorrectly predicted a delocalized degenerate ground state. In contrast, functionals that take strong correlation effects into account predicted a localized solution, in agreement with spin resonance experiments. The results, obtained using HSE hybrid, atomic self-interaction corrected and LSDA+U functionals, provided a number of constraints on the possibility of ferromagnetism in hole-doped MgO.

Polaronic Distortion and Vacancy-Induced Magnetism in MgO. A.Droghetti, C.D.Pemmaraju, S.Sanvito: Physical Review B, 2010, 81[9], 092403