The bound and quasibound levels of 6Li2 <i>a</i> 3Σ+<i>u</i>

Abstract

Rotationally resolved 6Li2 2 3Πg→a 3Σ+u fluorescence spectra have been obtained by perturbation facilitated optical–optical double resonance spectroscopy. Principal molecular constants for the a 3Σ+u first excited state of 6Li2 are (2σ uncertainties): Te =8180.9±5.4 cm−1, ωe =73.0±1.4 cm−1, ωexe =3.95±0.14 cm−1, Re =4.13±0.08 Å, and De =336.0±5.4 cm−1. Transitions into 0≤v≤6 and N=18, 20, 31, 33 were observed and the total number of bound rotation–vibration levels was computed to be 193 for the a 3Σ+u state of 6Li2.