On the lowest-lying states and electronic structure of the ScN+ and ScP+ isovalent ions Original Research Article

The primary purpose of this investigation is to compare the electronic structure and stability of the ScN+ and ScP+ isovalent systems. These cations have quasi-degenerate electronic states requiring extensive configuration interaction. CIPSI (Configuration Interaction by Perturbation of a multiconfiguration wavefunction Selected Iterative) wavefunction have been used to determine the lowest electronic states of both ions. Only two states are fairly bound, namely 2Σ+ and 2Π. Contrary to a previous theoretical study, the two isovalent species ScN+ and ScP+ are found similar with regard to their lowest 2Σ+ ground state and first 2Π excited state. The magnitude of the 2Σ+–2Π splitting in ScP+ was computed by several ab initio methods: