Electronic correlation effects, usually associated with open d or f shells, have so far been considered in p orbitals only sporadically for the localized 2p states of first-row elements. It was demonstrated that the partial band occupation and the metallic band-structure character as predicted by local density calculations for II-VI materials containing cation vacancies was removed when the correct energy splitting between occupied and unoccupied p orbitals was recovered. This transition into a Mott-insulating phase dramatically changed the structural, electronic and magnetic properties along the entire series (ZnO, ZnS, ZnSe and ZnTe), and impedes ferromagnetism. Thus, important correlation effects due to

open p shells exist not only for first-row (2p) elements, but also for much heavier anions like Te (5p).

Electronic Correlation in Anion p Orbitals Impedes Ferromagnetism Due to Cation Vacancies in Zn Chalcogenides. Chan, J.A., Lany, S., Zunger, A.: Physical Review Letters, 2009, 103[1], 016404