THE HYPERFINE STRUCTURE OF THALLIUM CHLORIDE

This research was supported by the U. S. Atomic Energy Commission and by the Michigan Memorial Phoenix Project. $^{1}$ J.C. Zorn, T.C. English, J.T. Dickinson, and D.A. Stephenson, J. Chem. Phys. 45, 3731 (1966). $^{2}$ R.O. Carlson, C.A. Lee, and B.P. Fabricand, Phys. Rev. 85, 784 (1952). $^{3}$ H.J. Zeiger, D.I. Bolef, Phys. Rev. 85, 788 (1952).Author Institution: Randall Laboratory of Physics, The University of MichiganThe hyperfine interaction constants of TlCl have been calculated from the radiofrequency spectra. The transition frequencies were measured with a molecular beam electric resonance spectrometer under conditions of very weak electric and magnetic $fields.^{1}$ An experimental linewidth of 500 Hz allowed us to determine for the first time the values of the tensor and scalar parts of the spin-spin interaction, $C_{3}$ and $C_{4}$. The quadrupole coupling constant for the chlorine nucleus, eqQ, and the spin-rotation coupling constants, $C_{C^{1}}$ and $C_{T^{1}}$, have been determined with greater precision than was possible in earlier $investigations.^{2,3}$ The calculated constants (in kHz) for all four isotopic species and several rotational and vibrations states are: [FIGURE