ENERGY-DEPENDENT VALENCE PHOTOELECTRON-SPECTRA OF SF6 - AB-INITIO CALCULATIONS AND MEASUREMENTS

Ab initio calculations of branching ratios and cross-sections for inne r- and outer-valence levels of SF6 have been carried out by means of t he static exchange (STEX) approximation including full intrachannel in teraction. The calculations cover an energy region up to 90 eV for the outer and 130 eV for the inner valence molecular levels and the resul ts are compared with experimental data. It is shown that the molecular orbital static exchange method successfully reproduces the strong mul tiple resonances in the near continuum. The resonances and the energy dependence of the photoionization cross-sections have been used to set tle some assignment problems in the valence photoelectron spectrum of SF6. Photoelectron spectra associated with the 2e(g), 3(1u) and 4a(1g) inner valence orbitals show significant variations in the electronic state branching ratios at electron kinetic energies around 60 eV. Thes e features are well reproduced by the present calculations. (C) 1998 E lsevier Science B.V, All rights reserved.