New potential energy surface for the HCS(+)-He system and inelastic rate coefficients

Marie-Lise Dubernet; Ernesto Quintas-Sánchez; Philip Tuckey

doi:10.1063/1.4926839

New potential energy surface for the HCS(+)-He system and inelastic rate coefficients

J Chem Phys. 2015 Jul 28;143(4):044315. doi: 10.1063/1.4926839.

Authors

Marie-Lise Dubernet¹, Ernesto Quintas-Sánchez¹, Philip Tuckey²

Affiliations

¹ LERMA, UMR8112, PSL Research University, Observatoire de Paris, Sorbonne Universités, UPMC Univ Paris 06, CNRS, 5 Place Janssen, 92195 Meudon, France.
² LNE-SYRTE, PSL Research University, Observatoire de Paris, Sorbonne Universités, UPMC Univ Paris 06, CNRS, LNE, 61 Av. de l'Observatoire, 75014 Paris, France.

PMID: 26233137
DOI: 10.1063/1.4926839

Abstract

A new high quality potential energy surface is calculated at a coupled-cluster single double triple level with an aug-cc-pV5Z basis set for the HCS(+)-He system. This potential energy surface is used in low energy quantum scattering calculations to provide a set of (de)-excitation cross sections and rate coefficients among the first 20 rotational levels of HCS(+) by He in the range of temperature from 5 K to 100 K. The paper discusses the impact of the new ab initio potential energy surface on the cross sections at low energy and provides a comparison with the HCO(+)-He system. The HCS(+)-He rate coefficients for the strongest transitions differ by factors of up to 2.5 from previous rate coefficients; thus, analysis of astrophysical spectra should be reconsidered with the new rate coefficients.