Ionic photofragmentation cross sections of the HS+ H2S+ and HCl+ molecular ions near the 2p threshold

Abstract

The absolute cross sections for the production of X2+ and X3+ ions following absorption of monochromatized SOLEIL synchrotron radiation by the HX+ hydride molecular ions (X = S,Cl) are presented as a function of photon energy in the region of the X 2p ionisation thresholds (180 eV and 220 eV for sulphur and chlorine, respectively). The experimental results are interpreted with the help of extensive ab initio density functional theory (DFT) and post-Hartree-Fock configuration interaction calculations including spin-orbit coupling to compute the absorption oscillator strengths of the X 2p core excitations to valence and Rydberg states. In order to account for all the experimental features,the calculations must include vibrational dynamics and spin-orbit coupling. Similar experimental data are also presented for the sulfanyumil H2S+ molecular ion.