Low-lying electronic states of In2As2, In2As2+ and In2As2−

Geometries and energy separations of 16 electronic states of In2As2, three electronic states of In2As2+ and the ground state of In2As2− are computed using the relativistic complete active space multi-configuration self-consistent field followed by multi-reference singles+doubles configuration interaction (MRSDCI) computations that included over a million configurations. All three species have rhombus geometries with 1Ag, 2B3g and 2B1g ground states, for In2As2, In2As2+ and In2As2−, respectively. Adiabatic ionization, electron affinity and dissociation energies are computed. Our computed results are compared with the negative ion photoelectron spectra of In2P2− of Xu et al.