Physical Review A 52 (1995) 4665-4677.
Electron-impact core excitation of SF6- I. S 2p, S 2s, and F ls spectroscopy
James T. Francis,1 Cássia C. Turci,1,2 Tolek Tyliszczak,1 G. Gerson B. de Souza,2 Nobuhiro Kosugi,3 and Adam P. Hitchcock1
1Department of Chemistry, McMaster University, Hamilton, Ontario, Canada L8S4MI
2Instituto de Quimica, Universidade Federal do Rio de Janeiro 21910-900 Rio de Janeiro, Brazil
3Institute for Molecular Science, Myodaiji, Okazaki 444, Japan
(Received 7 April 1995)

Electron energy-loss spectra (EELS) of SF6 have been recorded in the region of S 2p, S 2s, and F ls excitation, using both dipole and nondipole electron-scattering conditions. Impact energies between 700 and 3200 eV and scattering angles between Oº and 30º were used. Relative to dipole EELS or photoabsorption, there are large intensity redistributions in both the S 2p and S 2s s spectra under nondipole conditions. In contrast, the F ls spectrum is essentially the same in near-dipole and nondipole scattering regimes. A higher order electric multiple S 2p spectra feature is observed at 181 eV. It has an unusual multipeaked line shape whose components are more closely spaced than the typical 1.15-eV S 2p spin-orbit splitting. It is attributed to the overlap of several quadrupole-coupled states, which are likely associated with the [S 2p(tlu)-I,tlu] configuration. Ab initio self-consistent field calculations for various open-shell S 2p excited states are used to assist spectral assignments.

©1995 The American Physical Society