THE ELECTRONIC STRUCTURE OF PrO

$^{1}$E.A. Shenyavskaya, J. Mol. Spectrosc. 47, 355 (1973).Author Institution:As is typical of the rare earth oxides, PrO has many low-lying electronic states and many incompletely analyzed electronic transitions are $know.^{1}$ By high precision ($0.001 cm^{-1}$), Doppler-limited, selective-fluorescence-detected, cw dye laser excitation spectroscopy, we have analyzed the rotational and $^{141}$Pr(I = 5/2) hyperfine structure of several electronic transitions. Spectra of narrow-bandwith laser excited resolved fluorescence $(\sim 0.5$ $cm^{-1}$ precision) sample numerous low-lying electronic states and provide energy-linkages between several of the transitions tabulated by $Shenyavskaya.^{1}$ For example, the lower levels of the XXI and XVII systems are, respectively, $\Omega^{\prime\prime} = 4.5$ and 3.5 with the 4.5 level at $217 cm^{-1}$ higher energy. The energy level diagram of PrO and the configurational parentage of several electronic states will be discussed