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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(t_lu)-I,t_lu]
configuration. Ab initio self-consistent field calculations for
various open-shell S 2p excited states are used to assist spectral
assignments.}