Knowledge Bank

We present the spectra of three hot band transitions of $ArHF(3001)\leftarrow (0001),(3101)\leftarrow (0001)$ and $(3111)\leftarrow (0001)$ near $11400cm-1$ obtained by intracavity laser induced fluorescence. The spectroscopic constants of these transitions are determined to be $\nu 0=11347.2426(2)cm-1,11405.5718(6)cm-1,11417.3888(6)cm-1$ and $B=0.095546(32)cm-1,0.090617(37)cm-1,0.090827(15)cm-1$, respectively. Of particular importance is the $(3001)\leftarrow (0001)$ hot band transition, as it precisely determines the vdW stretching frequency of $46.894cm-1$ for ArHF at $vHF=3$. The vdW stretching frequency increases 21.2% upon $HFv=3\leftarrow 0$ valence excitation. The present experimental results are in reasonable agreement with predictions by Hutson's ArHF $H(6,4,2)$ $potential.a$ A high-level 3-dimensional ab initio ArHF potential with H-F distances ranging from $0.7-1.9$ {\AA}will be presented. Recent progress in the determination of HF product rotational state distribution of HF-complexes at $vHF=3$ following the vibrational predissociation, using a newly constructed Michelson interferometer in conjunction with intracavity laser fluorescence, will be also presented.