We report on the observation of a gerade Rydberg electronic energy state of Cd₂ van der Waals (vdW) complex vibrationally cooled in a free-jet expansion beam. Cd₂ in the beam were excited from the $X^1{0}_g^{+}(5^1{S}_0)$ ground via the $b^3{0}_u^{+}(5^3{P}_1$) intermediate to the final gerade state using optical–optical double resonance (OODR) method. A pronounced vibrational progression with partly resolved isotopologue components was recorded and analyzed. The analysis of isotopic separation indicated the excitation to high vibrational levels (${\upsilon }^{\prime }\approx 50$). A comparison with the result of ab initio calculations reveals, that Cd₂ was most probably excited to the ${}^3{1}_g$ -state correlating with the $6^3{S}_1$ atomic asymptote.

我们报告关于Cd ₂范德华（vdW）复合体在自由射流扩展梁中振动冷却的gerade Rydberg电子能态的观察结果。光束中的Cd ₂从$X^{\mathrm{1个}}{0}_G^{+}（5^{\mathrm{1个}}{\mathrm{小号}}_0）$地面通过的$b^3{0}_{ü}^{+}（5^3{P}_{\mathrm{1个}}$）使用光学-光学双共振（OODR）方法在最终gerade状态中间。记录并分析了具有部分分解的同位素同位素组分的明显振动过程。同位素分离的分析表明激发到高振动水平（${\upsilon }^{\prime }\approx 50$）。与从头算计算结果的比较表明，Cd ₂最有可能被激发。${}^3{\mathrm{1个}}_G$ 状态与 $6^3{\mathrm{小号}}_{\mathrm{1个}}$ 原子渐近线。