Electron Population Analysis by Full-Potential X-Ray Absorption Simulations

We present the first successful attempt at calculating cluster full-potential x-ray absorption near-edge structure (XANES) spectra, based on the finite difference method. By fitting XANES simulations onto experimental spectra we are able to perform electron population analysis. The method is tested in the case of Ti $K$-edge absorption spectrum in ${\mathrm{TiO}}_2$, where the amount of charge transfer between Ti and O atoms and of the screening charge on the photoabsorber is obtained taking into account both dipolar and quadrupolar transitions.