A spectroscopic study of the 3(1) pi g Rydberg state of 7Li2.

With pulsed optical-optical double resonance (OODR) fluorescence excitation spectroscopy Rydberg states of 7Li2 in the energy region of 35,500-38,000 cm-1 were studied and 146 transitions into the 3(1) pi g state of 7Li2 were measured. They were assigned to 10 vibrational levels of the 3(1) pi g state. A new set of Dunham constants, RKR potential curve, and Franck-Condon factors for the transitions form the A 1 sigma u+ state are derived. The perturbations between the 4(F)1 sigma g+, 5 (1) sigma g+, 6 (1) sigma g+, 2 (G) 1 pi g Rydberg states with the 3 (1) pi g state are discussed. The lambda-doubling splitting of the observed levels can be ignored with our accuracy (0.2 cm-1).