Multi-center interference effects on generalized oscillator strengths for the valence-shell electronic excitations of CF₄

We report on multi-center interference effects on valence electronic excitations in CF₄ induced by electron impact. Generalized oscillator strength (GOS) profiles for Rydberg transitions have been derived from electron energy loss spectra measured at an impact energy of 3.0 keV. We have also performed a theoretical calculation at the equation-of-motion coupled cluster singles and doubles level. The calculation has demonstrated the existence of interference features in the GOS profiles for 3s Rydberg transitions. Furthermore, a secondary maximum being interpreted as indicative of interference effects has actually been found in the experimental GOS profile for the 13.8 eV transition band.