On the 5d1Πg→ 21Σ+uand 5d1Πg→C1ΠuFluorescence in7Li2

Following excitation of the 5d1ΠgRydberg state of7Li2by optical–optical double resonance, fluorescence has been observed in the infrared region to the 21Σ+uandC1Πustates. Analysis of high-resolution Fourier transform spectra yields term energies and rotational constants of the lowest seven vibrational levels of the inner well of the 21Σ+u“double minimum” state. The equilibrium term value and dissociation energy have been determined to beTe= 30101.45 ± 0.12 cm−1andDe= 5621.3 ± 0.2 cm−1. Thev= 0 and 1 levels of theC1Πustate have been analyzed, resulting in new values ofTe= 30551.0 ± 0.1 cm−1andDe= 7773.3 ± 0.2 cm−1.