Electronic excitations: Ab initio calculations of electronic spectra and application to zirconia ZrO₂, titania TiO₂ and cuprous oxide Cu₂O

We address the question of the prediction and interpretation of experimental spectra obtained by the excitation of valence electrons, such as valence photoemission spectra, Bremsstrahlung isochromat spectra (BIS), electron energy-loss spectra (EELS) or absorption spectra using ab initio methods. We discuss which levels of theory are appropriate for which experiment, from ground-state density-functional calculations to the random phase approximation and time-dependent density-functional methods, and also discuss many body effects in the quasiparticle framework. We show applications of these methods to three different transition-metal oxide systems: ZrO₂, TiO₂ and Cu₂O.