Electronic states of Ga3Si, GaSi3, and their ions

The equilibrium geometries and electronic states of Ga3Si, GaSi3, and their ions are investigated using the complete active space self-consistent-field (CASSCF) and DFT(B3LYP)/CCSD(T) techniques. The 2B1, 3B1, and 1A1 states in C2v symmetry with a planar quadrilateral geometry are found to be the ground states of Ga3Si, Ga3Si+, and Ga3Si−, respectively. On the other hand, the ground states of GaSi3, GaSi3− are also predicted to undergo Jahn-Teller distortion to the 2A″ and 1A′ states in Cs with a distorted triangular pyramid geometry, respectively, whereas that of GaSi3+ is found to be the 1A1 state in C3v with symmetric triangular pyramid structure. Binding energies, electron affinities, ionization energies of Ga3Si and GaSi3 are computed at the CCSD(T)/QCISD(T) level and discussed.