Pulsed Optical-Optical Double Resonance Spectroscopy ofGeradeExcited Electronic States inLi2

Abstract
Optical-optical double resonance using two nitrogen-laser-pumped dye lasers has been used to make the first spectroscopic study of the hitherto unobserved gerade excited electronic states of Li27. Three Σg+1 and two Πg1 states are observed. Molecular constants in cm1 for one of the Πg1 states are Te=31868.02, ωe=229.71, ωeXe=1.654, Be=0.46986, αe=0.005959, De=7.301, and r3=3.198 Å.