Unusual geometries and spectroscopic properties of electronic states of In 2N 2

Abstract

Twenty electronic states of In 2N 2 are computed using a complete active space multi-configuration self-consistent field followed by multi-reference singles + doubles configuration interaction (MRSDCI) computations. In contrast to other III–V tetramers, In 2N 2 exhibits nearly degenerate T-shaped triplet states and linear In–In–N–N 3Σ − state. The 1A g state with a rhombus structure was found to be 0.94 eV higher. Our computations show that anion photodetachment spectra of In 2N 2 could be substantially different from the spectra of Ga 2P 2 and related tetramers observed by Neumark and coworkers. The computed vibrational and Raman spectra are provided.