Theoretical Investigation of the Electronic Structure and Spectra of Mg²⁺He and Mg⁺He

Abstract

The ground and many excited states of the Mg(+)He van der Waals molecular system have been explored using a one-electron pseudopotential approach. In this approach, effective potentials are used to consider the Mg(2+) core and the electron-He effects. Furthermore, a core-core interaction is included. This has reduced the number of active electrons of the Mg(+)He, to be considered in the calculation, to a single valence electron. This has permitted to use extended Gaussian basis sets for Mg and He. Therefore, the potentianl energy and dipole moments calculations are carried out at the Hartree-Fock level of theory, and the spin-orbit effect is included using a semiclassical approach. The core-core interaction for the Mg(2+)He ground state is included using accurate CCSD(T) calculations. The spectroscopic constants of the Mg(+)He electronic states are extracted and compared with the existing theoretical works, where very good agreement is observed. Moreover, the transition dipole function has been determined for a large and dense grid of internuclear distances including the spin-orbit effect.

Data Needs for Modeling Low-Temperature Non-Equilibrium Plasmas: The LXCat Project, History, Perspectives and a Tutorial

“…Data for 424 positively or negatively charged atomic and molecular ions is available for a wide variety of elements across the periodic table of elements (see also Figure 6). Some of the notable changes and extensions since 2016 in the Viehland database involve ions of C [162,163], Co, Cr, and Ni [164], Gd [165], K [166,167], Mg [168][169][170][171], O [172,173], S [174], and Si [175].…”

Spectroscopic Properties of the Alkali–Krypton Diatomic M–Kr (M = Rb, Cs, and Fr) van der Waals Systems Including the Spin–Orbit Coupling

“…For each atom (λ = Rb, Fr, or Kr), the core polarization effects are described by the following effective potential: where λ is for either the M + (M = Rb, Cs, and Fr) core or the krypton atom, α is the dipole polarizability, and f is the electric field created by valence electrons and cores of each center. The used polarizabilities of the alkali ions were taken as 9.245 a 0 3 , 15.116 a 0 3 , and 20.38 a 0 3 for Rb, Cs, and Fr, respectively, − whereas that of the krypton atom was taken as 17.0 a 0 3 …”

“…Interactions of alkali metal atoms with rare gas atoms are of great importance in several areas of physics and chemistry. These interactions have been investigated experimentally − and theoretically − for many years and for many systems. In fact, they are considered as model systems for van der Waals molecules.…”

“…Theoretically, there are several calculations − of the interactions between the alkali atoms with noble gas atoms. The M­( 2 S) + Rg pairs (M = alkali; Rg = rare gas) were investigated by Baylis using pseudopotential method and spin–orbit coupling.…”

“…Goll et al studied the M–Rg (M = Li, Na, K, Rb, and Cs; Rg = Ar, Kr, and Xe) systems using the short-range gradient-corrected density functional method combined with long-range coupled-cluster methods (CCSD, CCSD­(T)). More recently, the van der Waals systems involving alkali and alkaline-earth atoms interacting with rare gas atoms have been investigated by our group − using a one-electron pseudopotential approach, large Gaussian basis sets, and full configuration interaction.…”