MULTIREFERENCE CONFIGURATION-INTERACTION CALCULATIONS ON THE SYSTEMS XE-2+ AND XE-3+

Potential curves for the ground (2Σu+) and the three lowest excited states of the Xe2+ dimer ion (2Πg,2Πu,2Σg+) have been calculated using pseudopotentials in MRD-CI (multi-reference single and double excitation configuration interaction) calculations. Spin-orbit interaction - leading to the six states 1.(1/2)u, 1.(3/2)g, 1.(3/2)u, 1.(1/2)g, 2.(1/2)u, 2.(1/2)g - has been taken into account using a semiempirical technique [1]. Subsequently, starting with a relaxed Xe2+ ion in its ground state, the potential energy surface for the system Xe-Xe2+ was studied. We found that the collinear approach of the Xe atom leads to the most stable geometry. This is a linear symmetric molecule with bond lengths of 6.38 bohr. In the best T-shaped structure, the Xe atom is 7.83 bohr away from the midpoint of the Xe2+ (r=6.1 bohr) dimer. The calculated binding energy of 0.25 eV for the equilibrium structure of the Xe3+ molecule (i.e. the linear symmetric geometry), is in very good agreement with experimental results of 0.27 ± 0.02 eV [2]. © 1990 Springer-Verlag.