Electronic spectrum of the NpO22+ and NpO2+ ions

The ground and excited states of the linear NpO22+ and NpO2+ ions have been calculated using relativistic spin-orbit configuration interaction methods based on effective core potentials. The f --> f transitions and some charge-transfer transitions have been calculated for both ions and compared with experiment wherever possible. Various types of analysis are used to gain a better understanding of the types and patterns of electronic states.