Ab Initio Investigation of MgXe , Its Cation Mg ⁺ Xe and Clusters Mg ⁺ Xe M. Bejaoui, S. Awali, W. Zrafi, J. Dhiflaoui, H. Berriche

ABSTRACT

One and two electron pseudopotential approaches were employed to investigate the electronic and spectroscopic properties of the Mg ⁺ Xe and MgXe van der Waals complexes. In this study, potential energy curves (PECs) were computed at the SCF level for the Mg ⁺ Xe system, whereas both SCF and full configuration interaction (FCI) calculations were performed for the neutral MgXe complex. In addition, the core–core interaction, denoted as Mg ²⁺ Xe, was treated using the CCSD(T) method. Furthermore, spin–orbit coupling effects were explicitly included for the first excited B ² Σ ⁺ and A ² Π electronic states. Spectroscopic parameters obtained for the ground and low‐lying excited states are compared with existing experimental and theoretical results, showing good agreement and contributing to a deeper understanding of the interaction between Mg and Xe in various electronic states. The temperature dependence of the absorption spectrum of a Mg atom adsorbed on Xe _n ( n  = 1–7) clusters is also investigated using a combined Monte Carlo (MC) method with basin hopping global optimization to simulate the geometries of the xenon clusters in the 3s–3p transition at temperature T. Transition dipole moments are also calculated for the X ² Σ ⁺  → A ² Π ₁ / ₂ , ₃ / ₂ and X ² Σ ⁺  → B ² Σ ⁺ ₁ / ₂ transitions.