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 actua l physical quantities to characterize metallic properties is used. The paper reports a calculation of the shape of the FS of alkali metals a long three principal directions [100], [110] and [111] based on a loca l model potential. The effect of four different forms of dielectric fu nctions on asphericity in the FS, is examined explicitly. A good overa ll agreement found between experiment and theory, with regard to asphe ricity in the FS, confirms the general correctness of the empirical fo rm factor employed in the investigation.