This paper reports the first experimental observation of the doubly ex
cited valence (2p+2p)(3) Sigma(g) state of Li-7(2). We used cw perturb
ation-facilitated optical-optical double resonance (PFOODR) fluorescen
ce excitation and resolved fluorescence spectroscopic techniques. All
the observed levels have been detected through perturbations by the 2.
(IIg)-I-3 state. The deperturbed primary molecular constants of this 1
(3) Sigma(g)(-) state are T-e=34 045.354(43) cm(-1), omega(e)=216.820
(37) cm(-1), B-e=0.673 69(47) cm(-1), R(e)=2.670 81(94) Angstrom and D
-e=4279.306(43) cm(-1). The equilibrium internuclear distance of the 1
(3) Sigma(g)(-) state is smaller than that of the X (1) Sigma(g)(+) g
round state.