Singular structure in the density of levels of simple metals

Local pseudopotential components V_→K are available in many of the simpler metals, either from measurement or by direct computation. Given these it is shown that by invoking generally no more than a three-band model throughout the zone, a straightforward method is available for obtaining the principal features of the density of levels. Certain of these features, those recognizably due to the form of the bands near zone planes, for example, have their counterparts at zone-plane intersections and these are shown to arise from Van Hove singularities on otherwise nearly-free-electron band structures. In the case of aluminum, the example used to illustrate the method, it is shown that significant single-particle band-structure effects are present in the density of levels at the Fermi energy.