Electron detachment energies of AlAs− and AlAs2−

The ground and low-lying excited states of AlAs−, AlAs, AlAs2−, and AlAs2 are studied using DFT and CCSD(T) approximation. AlAs− has a 2Σ+ ground state with a 2Π state 1.08 kcal/mol above. AlAs has a 3Σ− ground state with the lowest 3Π and 1Σ+ states at 2.32 and 15.14 kcal/mol, respectively. Adiabatic electron affinity (AEA) of AlAs is 1.91 eV at the CCSD(T) level. AlAs2− and AlAs2 have 1A1 and 2B2 ground states, respectively. CCSD(T) predicts the AEA of AlAs2 to be 2.07 eV. Electron detachment processes from AlAs− and AlAs2− ground states are presented and discussed.