RESONANT X-RAY-EMISSION SPECTROSCOPY OF MOLECULAR-OXYGEN

Resonant soft x-ray emission spectroscopy has been applied to study th e issue of symmetry breaking upon core-hole excitation in molecular ox ygen. The results provide direct evidence that the inversion symmetry is not broken in the core-excited states. Furthermore, the experiments themselves demonstrate a new experimental technique of broad applicab ility for studies of electronic structure and excitation dynamics in f ree atoms and molecules.