Resonant decay spectra for energetically unselective excitation exemplified by the broadband resonant Auger spectrum of HF

The interpretation of resonant decay spectra of molecules resulting from an energetically unselective excitation may be very complex: a large number of core-excited states is accessible by broadband excitation and thus decay contributions of all of these states can be found in the observed spectra. For an understanding of the spectra a knowledge of the potential curves of all core-excited and final states involved as well as information about the populated intermediate states is necessary. In this paper, we demonstrate this by studying the broadband resonant Auger spectrum of hydrogen fluoride in detail. A comparison with the experimental spectrum obtained after electron-impact excitation will be drawn. For this paper the needed potential curves have been computed using extended ab initio multireference configuration-interaction calculations. The information on the core-excited states populated by electron impact is obtained by calculation of the electron energy-loss spectrum of HF and comparison with the corresponding experimental spectrum.