Soft X-ray absorption at the O K-edge in rutile-type natural oxides

Theoretical modelling of XAS spectra was carried out. Details of O 1s absorption spectra like the presence of a single post-edge feature for plattnerite and cassiterite may be interpreted by the separation or mixing between O 2p and M nd plus mixing with M ns and np states. Spectra features are commented in relation to crystal structure details but the energy shift assigned for the O K-edge in cassiterite still lacks a plausible explanation.