The Low Lying Electronic States of GeO

The A 1Π-X 1Σ+ band system in 74Ge16O and 74Ge18O is analyzed and the local perturbations of the A 1Π state are assigned. Four new electronic states are reported, namely the d 3Δ, e 3Σ-, C 1Σ- and D 1Δ states. Vibrational numbering is determined from the isotopic shifts. The vibrational variations of the perturbation matrix elements are shown to be in agreement with single configuration arguments. The electronic spin-orbit parameter a+ and the Coriolis parameter b are determined. The molecular constants for the eight lowest electronic states are reported. Semi-empirical and isovalent relationships between spin-orbit and spin-spin constants are also discussed. The equilibrium constants for the A 1Π state and the four perturbing states are in cm-1: State Te ωe Be A 1Π 37 763.1 648.8 0.414 32 D 1Δ 32 715 591 0.362 2 C 1Σ- 32 475 591 0.362 2 e 3Σ- 32 214 600 0.362 2 d 3Δ1 30 492 597 0.362 2