Multiple-scattering approach to oxygen K near-edge structures in electron-energy-loss spectroscopy of alkaline earths

The multiple-scattering approach to the calculation of fine structure in inner-shell electron-energy-loss spectroscopy is based on a muffin-tin potential approximation. In order to extract information on atomic environment and charge transfer, it is essential to understand the relationship between the near-edge structures and the crystal potential. We compare the oxygen K near-edge structure of MgO, CaO, and SrO calculated with two commonly used ground-state muffin-tin potential models for ionic materials. Although the muffin-tin potential and the phase shifts are quite different, we found that these two models are both capable of yielding near-edge structure which is in reasonable agreement with the experimental spectra. Our results suggest that multiple-scattering calculations may not be able to differentiate between these two models for the muffin-tin potential. It appears that the near-edge structure is more affected by geometry than possible charge transfer.