The absolute cross section of the reactive collision of P⁺(³P) with D2: a combined theoretical and experimental study

Abstract

[EN]In this work, we combine theoretical and experimental methods to study the P+(3P)+D2 → PD++D reaction. As a result, the absolute cross section as a function of collision energy is obtained. Ex- perimentally, the cross section is measured using the guided ion beam technique (GIB), where P+ is produced by VUV photons at the SOLEIL synchrotron using PCl3 as a precursor. Theoretically, the cross section is calculated from rst principles. The potential energy surfaces of the three electronic states correlating to the P+(3P) are constructed by tting MRCI points, and reaction dynamics is performed on each of them independently, hence neglecting couplings. The total cross section is then obtained from the weighted contribution of each considered electronic state. Our ndings show a good agreement between the measured and calculated cross sections, with a small discrepancy indicating that spin-orbit and non-adiabatic coupling, not considered in this work, may play a role in this reaction. The results hereafter presented demonstrate that the chemistry of third-row atomic cations with molecular hydrogen is generally unfavoured, unlike their second-row homologues, thus manifesting the existence of boundaries to the use of the so-called chemical analogy (i.e., assuming the same chemical behaviour for elements belonging to the same group)