Ab initio interaction potentials of alkali metal (M = Na and K)–rare gas (Rg = He, Ne, Ar, Kr, Xe and Rn) complexes

AbstractSpectroscopic properties and potential energy curves of alkali metal (M = Na and K) – rare gas (Rg = He, Ne, Ar, Kr, Xe and Rn) van der Waals molecules in their ground states have been studied in detail using spin-restricted open-shell coupled cluster with single and double excitations and perturbative contribution of connected triple excitations (RCCSD(T)) methods. The core-valence correlation (CV) effect was found to be crucial for M-RG molecules containing heavy rare gas atoms. The electronic energies were corrected for the basis set superposition error (BSSE) using the counterpoise method. Energies were extrapolated to the complete basis set (CBS) limit using a two-point scheme. The permanent electric dipole moments, static electric dipole polarizabilities and long-range dispersion coefficients were also calculated. The computed spectroscopic constants, vibrational levels and rotational constants were reported for M-RG and good agreement with the available experimental and theoretical values were found.KEYWORDS: Van der Waals systemsopen-shell coupled clusterspectroscopic constants AcknowledgementsDi Liu: Conceptualisation, Data curation, Writing – original draft, Writing – review & editing. Xinyu Li: Software, Methodology, Writing – review & editing. Lulu Li: Review. Bing Yan: Supervision, Validation. Data availability Data will be made available on request.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by the National Natural Science Foundation of China (grant number 11874177, 12274178, and 11574114), the High Performance Computing Center (HPCC) of Jilin University and high performance computing cluster Tiger@ IAMP.