Theoretical study of electronic structure of rhodium mononitride and interpretation of experimental spectra

Potential energy curves of 22 electronic states of RhN have been calculated by the complete active space second‐order perturbation theory method. The X 1 Σ 0 + is assigned as the ground state, and the first excited state a 3 Π 0 + is 978 cm −1 higher. The 1 Δ(I) and B 1 Σ + states are located at 9521 and 13,046 cm −1 above the ground state, respectively. The B 1 Σ + state should be the excited state located 12,300 cm −1 above the ground state in the experimental study. Moreover, two excited states, C 1 Π and b 3 Σ + , are found 14,963 and 15,082 cm −1 above the X 1 Σ + state, respectively. The transition C 1 Π 1 –X 1 Σ 0 + may contribute to the experimentally observed bands headed at 15,071 cm −1 . There are two excited states, D 1 Δ and E 1 Σ + , situate at 20,715 and 23,145 cm −1 above the X 1 Σ + state. The visible bands near 20,000 cm −1 could be generated by the electronic transitions D 1 Δ 2 –a 3 Π 1 and E 1 Σ + 0 –X 1 Σ + 0 because of the spin–orbit coupling effect. © 2013 Wiley Periodicals, Inc.