Predissociation lifetimes of the b 3Π u state of Li 2 and the accidental predissociation of its A 1Σ u+ state

Abstract

Rotational coupling matrix elements between the b 3Π u and a 3Σ u + states of Li 2 have been calculated and b 3Π u predissociation lifetimes are obtained using our previously reported accurate potential curves. The lifetimes are only about one twelfth of values derived previously from perturbed lifetimes of the A 1Σ u + state. The accidental predissociation of this state is reinvestigated using theoretical spin-orbit coupling elements and good agreement is found with observed perturbed lifetimes. The spin-orbit coupling elements are only one third and one half of two earlier values determined from lifetime measurements and by ab initio calculation, respectively. The discrepancies are due in part to incorrect definitions of the coupling constants.