Electric quadrupole interaction of ${}_{}{}^{67}{}_{}{}^{}\mathrm{Zn}$ in zinc metal

The magnetic-resonance transition of the spin-(5/2) ground state of ${}_{}{}^{67}{}_{}{}^{}\mathrm{Zn}$ from the state $I_z$=1/2 to $I_z$=-1/2 has been studied in a single crystal of zinc metal as a function of crystal orientation relative to a magnetic field of 72 G. The small frequency deviations versus crystal orientation have been used to evaluate the electric quadrupole interaction $e^2$qQ/h as 12.19(2) MHz, the isotropic Knight shift as 0.236(6)%, and the anisotropic Knight shift as 0.013(2)%, at 4 K.