AN ESTIMATION OF CORE EXCITATION-ENERGIES APPLIED TO SF6 COMPARED TO SF2

A modelling of single core-hole states is proposed which consists in a dding an outer charge exerting on the remaining electrons a repulsion equivalent to the inner attraction resulting from the unscreening of t he nucleus. This equivalent charge can be estimated by comparing resul ts obtained from exact core-hole calculations on a simpler related mol ecule and from applying Koopmans' theorem to its valence ions. For dou ble core-hole states the total relaxation energy is computed by adding to the single relaxation energies an induced term estimated by the ge ometric average of the former. This model has helped assign two satell ites in the photoelectron spectrum of SF6 to singlet and triplet doubl e excitations.