Multireference Singles and Doubles Configuration Interaction Study of the Electronic States of GaSb

Abstract

Spectroscopic properties of low-lying electronic states of gallium antimonide (GaSb) have been studied by using ab initio based large scale multireference singles and doubles configuration interaction (MRDCI) calculations. Relativistic effective core potentials (RECP) of Ga and Sb are employed in the calculations. Potential energy curves of all 34 Λ−S states which correlate with the three lowest dissociation limits, namely, Ga(2Pu) + Sb(4Su), Ga(2Pu) + Sb(2Du), and Ga(2Pu) + Sb(2Pu) are computed. However, curves of 11 Λ−S states which dissociate into higher limits are also investigated. Spectroscopic properties of 22 Λ−S states are estimated. The ground state (X3Σ-) of GaSb is described by the ...σ2π2 configuration with re = 2.82 A and ωe = 161 cm-1. The ground-state dissociation energy (De) of GaSb has been calculated to be 1.30 eV. All 22 Λ−S states correlating with the lowest two asymptotes are allowed to mix through the spin−orbit coupling. The spin−orbit effects on the spectroscopic properties of low...