Upon checking previous correction methods involving many-body GW calculations for the O vacancy in ZnO, it was found that the GW quasi-particle shifts of the Vo defect states increased the splitting between occupied and unoccupied states due to self-interaction correction, and did not reflect the conduction- versus valence-band character. Also, the GW quasi-particle energies of charged defect states required large corrections for super-cell finite-size effects. Finally, the GW results were robust with respect to the choice of the underlying DFT or hybrid-DFT functional, and the (2+/0) donor transition lay below the mid-gap, close to previous predictions made by employing rigid band-edge shifts.

Many-Body GW Calculation of the Oxygen Vacancy in ZnO. Lany, S., Zunger, A.: Physical Review B, 2010, 81[11], 113201