On the 5d 1Πg → 2 1Σu+ and 5d 1Πg → C 1Πu fluorescence in 7Li2

Following excitation of the 5d (1)Pi(g) Rydberg state of Li-7(2) by optical-optical double resonance, fluorescence has been observed in the infrared region to the 2 (1)Sigma(u)(+) and C (1)Pi(u) states. 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 2 (1)Sigma(u)(+) ''double minimum'' state. The equilibrium term value and dissociation energy have been determined to be T-e = 30101.45 +/- 0.12 cm(-1) and D-c = 5621.3 +/- 0.2 cm(-1). The nu = 0 and 1 levels of the C (1)Pi(u) state have been analyzed, resulting in new values of T-e = 30551.0 +/- 0.1 cm(-1) and D-e = 7773.3 +/- 0.2 cm(-1). (C) 1998 Academic Press.