Interpretation of sulphur 2p XPS spectra in sulfide minerals by means of ab initio calculations

First-principles quantum chemical calculations have been used to reproduce S 2p x-ray photoelectron spectroscopy binding energies for a number of sulp hide minerals where accurate experimental data are available. Periodic calc ulations have been performed with the Hartree-Fock/density functional hybri d method B3LYP. Reasonable agreement between the calculated and experimenta lly observed S 2p(3/2) binding energies was achieved for the sulphides spha lerite, wurtzite, pyrite, galena and chalcopyrite, Based on these periodic calculations simple pseudo-hydrogen-saturated cluster models were construct ed that give reliable predictions for the spectra of all reference compound s, while also allowing for the treatment of more complex sulphide and polys ulphide structures inaccessible to present periodic approaches. Copyright ( C) 2000 John Wiley & Sons, Ltd.