On the Radiofrequency Spectrum of the Components of a Sodium Chloride Beam. The Dimerization of the Alkali Halides

The transitions ΔmI=±1, ΔmJ=0 for both Na and Cl were studied at high magnetic field in a beam produced by the evaporation of sodium chloride. The observed spectra could not be fully described in terms of the known internal interactions of a diatomic molecule or the interaction of a diatomic molecule with an applied field. It is suggested that the unexplained features of the spectra result from the presence in the beam of molecules of the type (NaCl)2. Similar effects have been observed in sodium fluoride and sodium iodide.