The method of electronic structure calculations for strongly correlated disordered materials is developed employing the basic idea of coherent potential approximation (CPA). Evolution of electronic structure and spin magnetic moment value with concen
tration $x$ in strongly correlated Ni$_{1-x}$Zn$_x$O solid solutions is investigated in the frame of this method. The obtained values of energy gap and magnetic moment are in agreement with the available experimental data.
The electronic structure in alkaline earth AeO (Ae = Be, Mg, Ca, Sr, Ba) and post-transition metal oxides MeO (Me = Zn, Cd, Hg) is probed with oxygen K-edge X-ray absorption and emission spectroscopy. The experimental data is compared with density fu
nctional theory electronic structure calculations. We use our experimental spectra of the oxygen K-edge to estimate the bandgaps of these materials, and compare our results to the range of values available in the literature.