Laser Spectroscopy of CeO: Characterization and Assignment of States in the 0-3 eV Range

Abstract Wavelength-resolved fluorescence excitation techniques have been used to record thirty one electronic transitions of CeO at a resolution of 0.03 cm −1 . All of the 16 states that correlate with Ce 2+ (4ƒ6 s )O 2− were characterized. Ω assignments were unambiguously determined from observations of the first lines in at least two rotational branches. Accurate term energies and rotational constants are reported. The results are in good accord with a ligand field theory model of the low-lying states. New assignments were established for four previously observed transitions, and spectra for three new excited states were analyzed. Ligand held theory calculations have been used in an attempt to provide configurational assignments for the excited states (including those from previous studies). Twenty-two states are tentatively assigned to the Ce 2+ (4ƒ6 p )O 2− configuration. Twelve others are tentatively assigned to Ce 2+ (4ƒ5 d )O 2− .