Jet-cooled laser-induced dispersed fluorescence spectroscopy of NiC: Observation of low-lying Ω = 0+ state

Laser-induced dispersed fluorescence spectra of 58Ni12C molecules, produced in a free-jet apparatus, have been studied. A new low-lying Ω = 0+ state has been observed at Te = 5178 (6) cm−1. Based on previous ab initio calculations this state is plausibly assigned as 0+ spin–orbit component of the first excited 3 Π state. The term energies of vibrational levels up to v = 10 for X 1 Σ + ground and v = 3 for Ω = 0+ states have been determined. The harmonic and anharmonic wavenumbers respectively equal to 833 (4) and 6.7 (13) cm−1 for Ω = 0+ state have been measured.