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

TL;DR

This study measures the ionization cross sections of HX+ ions near the 2p threshold using synchrotron radiation and interprets the results with advanced quantum chemical calculations, revealing detailed ionization dynamics.

Contribution

It provides new experimental cross section data and theoretical insights into the ionization processes of HX+ ions near the 2p threshold, including vibrational and spin-orbit effects.

Findings

Cross sections vary with photon energy near the 2p threshold.

Theoretical models including vibrational dynamics and spin-orbit coupling match experimental data.

Data for H2S+ ion also presented.

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.