Electronic Structure of a Series of Metals

Self-consistent calculations of the electronic structure, including screened exchange, are carried out for Li, Be, Na, Mg, Al, K, and Ca. Results are presented as orthogonalized plane wave (OPW) form factors. They agree well with values of these form factors estimated from splittings at symmetry points in the Brillouin zones obtained from existing band calculations. For calcium, the form factors are used to compute the Fermi surface in detail. The computed form-factor curves may be approximated within a few hundredths of a rydberg by the Fourier transform of a simple one-parameter potential in which the core is replaced by a delta-function repulsive potential. There are no apparent trends in the strength of this repulsion with valence nor with atomic number. The familiar dropping of the even state at the zone face in the alkali metals as the atomic number increases is to be associated with the larger atomic volume rather than with changes in the core potential. An attempt to treat copper in a similar manner indicated that the form-factor approach is quite inadequate for the noble metals.