XPS spectra were calculated for the S(2s) and S(2p) peaks before and after oxidation in order to show that the conventional way of analyzing experimental XPS spectra in terms of known bulk structures can lead to misinterpretations if specific surface structures, as calculated in this study, are neglected.
These calculations are beginning to explain the reactivity of galena in terms of the electronic surface structure of this mineral. They are helping us to understand the mechanism of early stages of the adsorption/oxidation process, especially when combined with experimental tunneling spectroscopy at specific sites.