SPECTROSCOPIC CONSTANTS AND POTENTIAL-ENERGY CURVES OF GA2, GA2-, AND GA2+

Spectroscopic constants and potential energy curves of 27 electronic states of Ga2, 14 electronic states of Ga2+, and 9 electronic states of Ga2- radicals are obtained by using complete active space MCSCF (CASSCF) followed by first-order configuration interaction (FOCI) and second-order configuration interaction (SOCI) methods. The ground states of Ga2, Ga2+, and Ga2- at all levels of theories are found to be 3IIu, 2Σg+, and 4Σg- states, respectively. The dissociation energies of all three species are comparable, but Ga2- is found to be more stable than Ga2 [De(Ga2) = 1.2, De(Ga2+) = 1.3, De(Ga2-) = 2 eV]. For Ga2 19 bound electronic states are found while for Ga2+ and Ga2- we find seven and five low-lying bound states, respectively. The adiabatic ionization potential and electron affinity of Ga2 are calculated as 5.62 and 1.04 eV, respectively. The electron affinity of Ga2 was found to be lower than that of GaAs, confirming O'Brien et al.'s experimental findings. © 1990 American Chemical Society.