Ab initio interaction potentials of the Ba, Ba+ complexes with Ar, Kr, and Xe in the lowest excited states

Dmitry S Bezrukov; Nadezhda N Kleshchina; Inna S Kalinina; Alexei A Buchachenko

doi:10.1063/1.5071457

Ab initio interaction potentials of the Ba, Ba⁺ complexes with Ar, Kr, and Xe in the lowest excited states

J Chem Phys. 2019 Feb 14;150(6):064314. doi: 10.1063/1.5071457.

Authors

Dmitry S Bezrukov¹, Nadezhda N Kleshchina², Inna S Kalinina¹, Alexei A Buchachenko¹

Affiliations

¹ Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, Building 3, Moscow 121205, Russia.
² Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow 119991, Russia.

PMID: 30769967
DOI: 10.1063/1.5071457

Abstract

The complexes of the Ba atom and Ba⁺ cation with the rare gas atoms Ar, Kr, and Xe in the states associated with the 6s → 5d, 6p excitations are investigated by means of the multireference configuration interaction techniques. Scalar relativistic potentials are obtained by the complete basis limit extrapolation through the sequence of aug-cc-pwCVnZ basis sets with the cardinal numbers n = Q, T, 5, combined with the suitable effective core potentials and benchmarked against the coupled cluster with singles, doubles, and non-iterative triples calculations and the literature data available for selected electronic states. Spin-orbit coupling is taken into account by means of the state-interacting multireference configuration interaction calculations performed for the Breit-Pauli spin-orbit Hamiltonian. The results show weak spin-orbit coupling between the states belonging to distinct atomic multiplets. General trends in the interaction strength and long-range anisotropy along the rare gas series are discussed. Vibronic spectra of the Ba and Ba⁺ complexes in the vicinity of the ¹S → ¹P° and ²S → ²P° atomic transitions and diffusion cross sections of the Ba(¹S₀, ³D_J) atom in high-temperature rare gases are calculated. Comparison with available experimental data shows that multireference calculations tend to underestimate the interaction strength for excited complexes.