Potential energy curves of low-lying electronic states of InN2, In2N and their cations and anions are investigated by the complete active space multi-configuration self-consistent field (CASSCF) followed by multi-reference singles + doubles configuration interaction (MRSDCI) computations. The neutral InN2 and In2N exhibit linear (2)Pi and (2)Sigma(+)(u) ground states, respectively. The InNN+ cation exhibits a linear C-infinity v ground state whereas In2N+ ion exhibits two nearly-degenerate singlet and triplet ground states. Whereas ln2N- is strongly bound with an adiabatic electron affinity of 2.07 eV, the electron affinity of InNN is only 0.2 eV. (c) 2006 Elsevier B.V. All rights reserved.