Spectroscopic Investigation of van der Waals Interactions in the Mg-Kr Diatomic System and Its Cations: Mg⁺-Kr and Mg²⁺-Kr

Several electronic states with Σ, Π, and Δ symmetries for both Mg⁺-Kr and Mg-Kr systems are studied using an ab initio approach. These calculations employ pseudopotential techniques, core polarization potentials, full configuration interaction calculations, and large basis function sets centered on the krypton and magnesium atoms. Additionally, the core-core interaction, represented by Mg²⁺-Kr, is accounted for using the CCSD(T) method. Moreover, the spin-orbit effect is included for the first excited B²Σ⁺ and A²Π electronic states, as well as for the X²Σ⁺ → A²Π_1/2,3/2 and X²Σ⁺ → B²Σ⁺_1/2 transition dipole moments. Our spectroscopic parameters for the ground state and lower excited states are compared with the available experimental and theoretical data.