Inner-shell electron energy-loss spectroscopy of SF6 at very high momentum transfer

Non-dipole S 2p and S 2s core excitation of SF₆ has been studied using inelastic electron scattering with variable scattering angles and impact energies (momentum transfer (K), 0.9<K²<113 a.u.⁻²). A non-dipole excitation at 181 eV is found to be the dominant S 2p spectral feature at large momentum transfer. A variable impact energy, fixed-K study shows that the first Born approximation fails under low impact energy, large scattering angle conditions. This study illustrates the importance of exploring a wide range of the inelastic scattering surface to ensure proper understanding of molecular spectroscopy and scattering dynamics.