Abstract
Observations of the de Haas-van Alphen effect in the ordered alloy βYZn (β-brass, or CsCl structure) reveal the existence of a small spherical pocket of carriers, together with an open sheet. There is at this time no satisfactory theoretical model to explain these results. An augmented-plane-wave (APW) calculation predicts a Fermi surface which is topologically inconsistent with the experimental results. There is some degree of agreement with the nearly-free-electron model, which is however of doubtful validity when yttrium is present. Possible modifications to the APW model are discussed.