Optical and excitonic properties of transition metal oxide perovskites by the Bethe-Salpeter equation

We present a systematic investigation of the role and importance of excitonic effects on the optical properties of transitions metal oxide perovskites. A representative set of 14 compounds has been selected, including 3 d (SrTiO₃, LaScO₃, LaTiO₃, LaVO₃, LaCrO₃, LaMnO₃, LaFeO₃, and SrMnO₃), 4 d (SrZrO₃, SrTcO₃, and Ca₂RuO₄ ) and 5 d (SrHfO₃, KTaO₃, and NaOsO₃) perovskites, covering a band gap ranging from 0.1 eV to 6.1 eV and exhibiting different electronic, structural, and magnetic properties. Optical conductivities and optical transitions including electron-hole interactions are calculated through the solution of the Bethe-Salpeter equation (BSE) with quasiparticle energies evaluated by the single-shot G₀W₀ approximation. The exciton binding energies are computed by means of a model BSE, carefully benchmarked against the full-BSE method, in order to obtain well-converged results in terms of k -point sampling. The predicted results are compared with available measured data, with an overall satisfactory agreement between theory and experiment.