Radio-Frequency and Microwave Spectra of 6Li127I by the Molecular-Beam Electric-Resonance Method

The radio‐frequency and microwave spectra of ⁶Li¹²⁷I have been observed by the molecular‐beam electric‐resonance method of molecular spectroscopy. Spectra of ⁶Li¹²⁷I in the first two vibrational states were obtained. From the J=1 radio frequency, Stark spectra values were obtained for the electric dipole moment μ, the iodine nuclear quadrupole interaction eqQ_I, and the iodine spin‐rotation constant c_I. The values of these constants are $$\begin{array}{ccc}& \text{v=0}& \text{v=1}\\ \mathrm{\mu \hspace{0.17em}(}\mathrm{debye})& \text{7.4285±0.001}& \text{7.5120±0.001}\\ {\mathrm{eqQ}}_{\mathrm{I}}\mathrm{\hspace{0.17em}(}\mathrm{Mc}/\sec )& \text{−198.780\hspace{0.17em}±0.005}& \text{−207.453\hspace{0.17em}±0.010}\\ c_{\mathrm{I}}\mathrm{\hspace{0.17em}(}\mathrm{kc}/\sec )& \text{7.7\hspace{0.17em}\hspace{0.17em}±0.4}& \text{7.8\hspace{0.17em}\hspace{0.17em}±0.6.}\end{array}$$ The observation of J=1→J=0 microwave transitions yielded the following rotational constants: $$\begin{array}{c}{B}_0\text{=15 304.895±0.005\hspace{0.17em}}\mathrm{Mc}/\sec ,\\ B_1\text{=15 153.316±0.009\hspace{0.17em}}\mathrm{Mc}/\sec .\end{array}$$