The (2 p, 2 p) 1 1Δ g State of 6Li 2: Fourier Transform Spectrum of the 1 1Δ g- B1Π u Transition

Abstract

The 1 1Δ g - B 1Π u transition of 6Li 2 has been observed in collisionally induced fluorescence following single frequency optical-optical double resonance excitation of the F 1Σ + g state using a ring dye laser with DCM dye. Spectra of the s and a symmetry levels were obtained separately, at high resolution, in the near-infrared region using a Fourier transform spectrometer. The molecular constants (Dunham coefficients) of the 1 1Δ g state have been calculated. Comparison of the constants and dissociation energy with ab initio calculations has shown that the 1 1Δ g state correlates with Li(2 p) + Li(2 p) and has a dissociation energy of 9579 ± 1 cm −1. The energy transfer process responsible for excitation of the 1 1Δ g state is discussed.