Theoretical investigations on electronic structures and spectroscopic properties of the diatomic lithium bismuthide cation

Abstract

We report a systematic theoretical investigation of the diatomic cation LiBi⁺, which is a previously not studied computationally species. High-level ab initio calculations characterize its structural, electronic and spectroscopic properties, focusing on low-lying Λ-S states correlated with the five lowest dissociation limits. Using the icMRCI+Q method with extended basis sets, we have obtained potential energy curves, spectroscopic constants and vibrational energy levels of the cation. The spin-orbit coupling effect demonstrates significant influence on the cation's electronic structure. We further quantify transition properties such as Einstein coefficients and radiative lifetimes. Benchmark computations for neutral LiBi validate our theoretical approach for the cationic system. Simulated single photo-ionization process of LiBi→LiBi⁺+e offers direct guidance for spectroscopic detections. The information obtained from this work could shed some light on future experimental designs and theoretical investigations of diatomic LiBi⁺.