Rotational structure of the Ï â€²=45â†Ï â€³=0 band of the 10u+(51P1)←X10g+ transition in 228Cd2: Direct determination of the ground- and excited-state bond lengths

A first-time recorded rotational structure of the 228Cd2 isotopomer is presented. From its analysis the rotational constants and bond lengths are determined. The obtained value of Re″ is close to that obtained with an assumption of a covalent admixture to the dominant van der Waals bonding of Cd2.