Knowledge Bank

Over the past few years, we have studied the spectra of several rare-earth oxide molecules and have explained their spectra using Ligand Field Theory. This paper will survey the most recent results of this investigation. We shall discuss the laser induced fluorescence spectra of several molecules. Resolved fluorescence spectra have been used to provide energy linkages between low lying states. High resolution excitation spectra were used for the rotational analysis, $\Omega$ assignments, examination of isotope spectra and, where possible, analysis of hyperfine structure. The experimental results will be discussed and compared with the Ligand Field Theory predictions. Among the oxides to be discussed are those of Dysprosium (DyO), Samarium (SmO) and Neodymium (NdO).