Electronic structure of PrO: An analysis summary

Abstract

The (0,0) bands of nine prominent electronic transitions, Systems X, XI, and XVI through XXII, in the wavelength region 500–800 nm were studied. High-precision (±0.005 cm −1), Doppler-limited, selectively detected cw-dye laser fluorescence excitation spectra for Systems XVI through XXII were recorded and analyzed. Definitive Ω assignments for the upper and lower states of these transitions were established from identified first lines in the P and R branches. Resolved fluorescence studies revealed 22 additional electronic transitions in the same wavelength region, many of which provide energy linkages between the upper or lower states of previously observed transitions. The comprehensive energy level diagram assembled from 31 electronic transition linkages comprises a total of 22 upper and lower electronic levels. Ω assignments and relative energies for the electronic states of the transitions studied (including Systems XIV and IX identified in fluorescence and the proposed assignment for System VI) are System Ω′ T′ 0 ( cm −1 ) Ω″ T″ 0 ( cm −1 ) VI 5.5 11102 4.5 2157 IX 4.5 16597 3.5 3887 X 5.5 13259 4.5 220 XI 5.5 13865 4.5 220 XIV 5.5 16595 4.5 2157 XVI 5.5 19169 4.5 3720 XVII 4.5 16597 3.5 0 XVIII 7.5 21321 6.5 3965 XIX 6.5 19687 5.5 2111 XX 5.5 18069 4.5 220 XXI 4.5 18885 4.5 220 XXII 5.5 19169 4.5 220 The relative energies are with respect to the lower state of System XVII, assigned here as the ground electronic state.