gFactor in Metallic Zinc

A calculation of the $g$ factor for the small "needles" of the Fermi surface of Zn has been carried on in the three-level approximation. It is shown that for fields parallel to the hexagonal axis, $g$ is expected to be large with an upper bound of 133. This result rules out two of the three possibilities determined by Stark from experiment. It is found that three possible orderings of the levels can give the observed results, and the energy gaps are estimated in each case; the lattice potential and the spin-orbit splitting are of the same order of magnitude. The variation of the $g$ factor with angle is in agreement with experiment.