Effects of plasmon pole models on the G 0 W 0 electronic structure of various oxides

The electronic properties of three different oxides (ZnO, SnO 2 and SiO 2 ) are investigated within many-body perturbation theory in the G 0 W 0 approximation. The frequency dependence of the dielectric function is either approximated using two different well-established plasmon-pole models (one of which enforces the fulfillment of the f-sum rule) or treated explicitly by means of the contour-deformation approach. Comparing these results, it is found that the plasmon-pole model enforcing the f-sum rule gives less accurate results for all three oxides. The calculated electronic properties are also compared with the available experimental data and previous ab initio results, focusing on the d state binding energies. The G 0 W 0 approach leads to significantly improved band gaps with respect to calculations based on the density functional theory in the local density approximation. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2012