The (001) surfaces, with O vacancies, were studied using first-principles calculations that were based upon the generalized gradient approximation. Strong local spin and orbital polarization of the Ti 3d electrons, induced by O vacancies, were found. In the SrO-terminated case, the occupied Ti 3d orbital had a strong 3z2–r2 character while, in the TiO2-terminated case, one of the t2g orbitals perpendicular to the surface was occupied on each of the 2 neighboring Ti atoms. By permitting spin polarization, the calculated electronic structures of the TiO2-terminated surface could explain the scanning tunnelling microscopy and spectroscopy data.Spin and Orbital Polarizations around Oxygen Vacancies on the (001) Surfaces of SrTiO3. Z.Fang, K.Terakura: Surface Science, 2000, 470[1-2], L75-80