ASPHERICITY IN THE FERMI-SURFACE OF ALKALI-METALS

The observed shape of the Fermi surface (ES) as a probe to examine the applicability and validity of a pseudopotential for calculating actual physical quantities to characterize metallic properties is used. The paper reports a calculation of the shape of the FS of alkali metals along three principal directions [100], [110] and [111] based on a local model potential. The effect of four different forms of dielectric functions on asphericity in the FS, is examined explicitly. A good overall agreement found between experiment and theory, with regard to asphericity in the FS, confirms the general correctness of the empirical form factor employed in the investigation.