On the Electronic Structure of NLi2 and PLi2, Ground and Low-Lying Excited States

Abstract

The ground states of the isovalent molecules NLi2 (X2Πu) and PLi2 (X2B1), along with some low-lying excited states (2B2,4Σg-, 2Σg-, 4Σu-, 2Σu-, and 2A1), have been examined using ab initio CISD, CASSCF, and MRCI methods in conjunction with relatively large correlation consistent basis sets. We report total energies, geometries, binding energies, Mulliken charges, energy gaps, and for certain states, potential energy curves. All states examined are bound with respect to the ground-state atoms N or P(4S) + 2Li(2S), while the mean binding energies N−Li and P−Li of NLi2 and PLi2 are 42.5 and 40.2 kcal/mol, respectively.