AN EXPERIMENTAL AND THEORETICAL-STUDY OF THE VALENCE SHELL PHOTOELECTRON-SPECTRUM OF SULFUR-DIOXIDE

The complete valence shell photoelectron spectrum of sulphur dioxide h as been studied using HeI, HeII and synchrotron radiation. The high re solution HeI and HeII excited spectra have allowed a detailed analysis to be made of the vibrational structure exhibited in the photoelectro n bands associated with ionisation from the outer valence orbitals. A new satellite band containing vibrational structure has been observed around 19 eV. The photoelectron spectra recorded with synchrotron radi ation demonstrate that the inner valence region contains several compl icated structures and is dominated by a prominent feature centred at a binding energy around 34 eV. Many-body Green's function calculations have been performed to evaluate the energies and pole strengths associ ated with the main lines and satellite states distributed throughout t he valence shell region, and an interpretation of some of the experime ntal features is proposed, based upon these predictions.