Electronic structures of Al4As, Ga4As and their anions

The equilibrium geometries, electronic structures and harmonic vibrational frequencies of Al4As, Al4As−, Ga4As and Ga4As− are studied employing DFT/B3LYP and CCSD(T) methods in conjunction with the 6-311+G(2d) and 6-311+G(2df) one particle basis sets. Neutral Al4As and Ga4As possess a C2v planar trapezoidal geometry. The anions have a C4v square pyramidal geometry. Electron detachment energies from the ground electronic states of the anions to several states of the neutral are presented and discussed. Adiabatic electron affinities of Al4As and Ga4As are computed to be 2.07 and 1.91 eV, respectively, using CCSD(T)//B3LYP level approximation.