Direct and inverse reactions of LiH+ with He(1S) from quantum calculations: mechanisms and rates

Abstract

The gas-phase reaction of LiH⁺ (X²Σ) with He(¹S) atoms, yielding Li⁺He with a small endothermicity for the rotovibrational ground state of the reagents, is analysed using the quantum reactive approach that employs the Negative Imaginary Potential (NIP) scheme discussed earlier in the literature. The dependence of low-T rates on the initial vibrational state of LiH⁺ is analysed and the role of low-energy Feshbach resonances is also discussed. The inverse destruction reaction of LiHe⁺, a markedly exothermic process, is also investigated and the rates are computed in the same range of temperatures. The possible roles of these reactions in early universe astrophysical networks, in He droplets environments or in cold traps are briefly discussed.