Potential energy curves for diatomic zinc and cadmium

Abstract

Molecular electronic structure theory has been applied to the low-lying electronic states of Zn2 and Cd2. Gaussian basis sets of size Zn (13s 9p 5d) and Cd (15s 11p 7d) have been optimized in atomic calculations on the ground 1S and excited 3P electronic states. The general contraction scheme of Raffenetti has been used to reduce these primitive Gaussian bases to size Zn (5s 4p 1d) and Cd (6s 4p 2d) without any degradation in the atomic SCF energies. Following X 1Σ+g ground state SCF calculations, full configuration interaction was performed for the four valence electrons. The resulting potential energy curves for Zn2 and Cd2 are, with some notable exceptions, qualitatively similar. In the case of Cd2, we have obtained potential curves which include spin–orbit coupling and have carried out a detailed analysis of the fluorescence intensity from the first 1u (3Σ+u) excited state.