Globally accurate potential energy surface for PH2 + (11 A′) by using the switching function formalism

Abstract

As an intermediate product of phosphorus compounds in astrophysical chemistry, has great significance in research on the systems. However, as a basis for studying its reaction mechanisms, lacks an accurate global potential energy surface (PES) and related dynamic reports. In this investigation, based on a multi-reference configuration interaction approach with Davidson correction, an accurate global many-body expansion PES for in its ground state was reported by fitting extensive ab initio energies, as calculated with the correlation-consistent basis set aug-cc-pVQZ. Meanwhile, the switching function formalism was adopted to explain and distinguish the transformation between and in one-body energy terms, which ensured the correct dissociation channel in the reaction process of . The topographical characteristics of the title system PES were meticulously contrasted with those in other literature reports, which were consistent with previous experimental and theoretical values. Subsequently, the time-dependent wave packet approach was adopted to calculate the reaction probability and integral cross-section for the reaction to verify the accuracy of the new PES. This dynamics study may help to further explain the thermochemical reactions of phosphorus-containing molecules in interstellar media.