Rotational analysis of the (57, 0) band of the D1u←X0g+ triplet-singlet transition in Hg2 produced in a free-jet expansion beam

Analysis of the rotational structure of the (57, 0) vibrational band of the D1u←X0g+ transition in Hg2 (natural abundance) is presented. From the analysis, the Bv′=57, Bv″=0, Be′ and Be″ rotational constants of the 398Hg2, 400Hg2, 402Hg2, 404Hg2 and 406Hg2, as well as the Re′=2.715Å and Re″=3.605Å bond lengths for the excited and ground electronic energy states involved in the transition are determined.