MASS-ANALYZED THRESHOLD IONIZATION OF LaO$_{2}$

Author Institution: Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055Lanthanum oxide, LaO$_{2}$, is produced in a pulsed laser-vaporization metal-cluster source and studied by mass-analyzed threshold ionization (MATI) spectroscopy. From the MATI spectrum, the adiabatic ionization energy of LaO$_{2}$ is determined to be 40134 (5) cm${^-}$${^1}$ or 4.976 (6) eV, and La${^+}$-O stretching and O-La${^+}$-O bending frequencies are measured as 656 and 120 cm${^-}$${^1}$. The measured ionization energy is about 3.0 eV lower than the value predicted by recent high-level ab initio calculations. In this talk, we will discuss the discrepancy between the experiment and theory and the electronic transition observed in our experiment