Electronic structure of GaAs2

Abstract
Complete active space MCSCF (CASSCF) followed by multireference singles + doubles configuration interaction (MRSDCI) calculations are carried out on the electronic states of GaAs2. Three electronic states, namely, 2B2, 2A1, and 2B1 are found among which the 2B2 state is the lowest state. The 2A1 state is about 29.4 kcal/mol above the 2B2 state while the CASSCF splitting of the 2B1 state with respect to the 2B2 state is 41 kcal/mol. The equilibrium geometries of all the three states are isosceles triangles. The 2B2 ground state exhibits greater As–As bonding and ionic character than the 2A1 state, which shows enhanced Ga–As bonding.