The predissociation of the 1(3)Sigma (-)(g) v greater than or equal to 10 l
evels of Li-7(2) has been observed by pulsed and continuous-wave perturbati
on-facilitated optical-optical double-resonance spectroscopy (PFOODR). Our
ab initio calculation shows that the inner wall of the 1(3)Sigma (-)(g) pot
ential intersects the 1 (3)Pi (g) repulsive potential at internuclear dista
nce R = 2.00 Angstrom. The predissociation is due to a DeltaS = 0, Delta La
mbda = +/-1 rotational-electronic interaction with the repulsive 1 (3)Pi (g
) state. (C) 2001 Academic Press.