Simulating fluorine K-edge resonant inelastic X-ray scattering of sulfur hexafluoride and the effect of dissociative dynamics

We report on a computational study of resonant inelastic X-ray scattering (RIXS), at different fluorine K-edge resonances of the SF6 molecule, and corresponding non-resonant X-ray emission. Previously measured polarization dependence in RIXS is reproduced and traced back to the local σ and π symmetry of the orbitals and corresponding states involved in the RIXS process. Also electron-hole coupling energies are calculated and related to experimentally observed spectator shifts. The role of dissociative S-F bond dynamics is explored to model detuning of RIXS spectra at the | F1s(−1)6a1g(1) 〉 resonance, which shows challenges to accurately reproduce the required steepness for core-excited potential energy surface. We show that the RIXS spectra can only be properly described by considering breaking of the global inversion symmetry of the electronic wave function and core-hole localization, induced by vibronic coupling. Due to the localization of the core-hole we have symmetry forbidden transitions, which lead to additional resonances and the width of the RIXS profile.