Shape resonances and partial photoemission cross sections of solid SF 6 and CCl 4

Abstract

Photoelectron energy distribution curves from solid films of SF 6 and CCl 4 have been measured in the photon energy range 10 ⩽ hr ⩽ 40 eV using synchrotron radiation. The binding energies, peak widths and relative partial cross sections have been determined. In the photoelectron spectra a 1:1 correspondence to the gas phase is observed for the occupied molecular orbitals, and a straightforward assignment of the occupied valence bands emerges. Furthermore, the cross sections of the individual orbitals show for both samples great similarities to the gas phase. For SF 6 detailed structures are visible in the cross sections which are only partly interpreted as shape resonances. A new assignment for the 6t 1u shape resonance is proposed and the resonance energies are related to X-ray absorption and electron scattering data. Furthermore a comparison of the total photoemission cross section to the optical reflection spectrum of solid SF 6 is presented. For CCl 4 less structures are ob served in the partial cross sections. They are all interpreted as shape resonances. An energetic scheme of the virtual orbitals is proposed for CCl 4.