THEORETICAL INTERPRETATION OF THE NIF SPECTRUM

We report a theoretical multiconfigurational calculation of the molecular electronic energy levels of the NiF molecule based on a ligand field model in which we have introduced the ligand polarizability. Results of the calculation show the extraordinary complexity of the low energy levels scheme of this molecule. The energy range extending from 0 to 8500 cm-1 is congested by no less than 26 states, most of them strongly mixed by spin-orbit interactions. These states are shown to pertain to the [3d9]2D and [3d8 (3F) 4s]4F overlapping supermultiplets and the [3d8 (3F) 4s]2F supermultiplet. The derived comprehensive energy linkage is in good agreement with fragmentary experimental observations and yields a tentative assignment of most of the observed transitions. In addition it provides a clue for further investigations. © 1993 Academic Press, Inc.