Electronic structure of cesium under pressure

Using the pseudopotential method we have calculated the band structure, the density of states, and the charge density for the conduction electrons in Cs for three cell volumes. The system was assumed to be fcc and the cell volumes V were chosen equal to 0.5V₀, 0.4V₀, and 0.3V₀ where V₀ is the cell volume at normal pressure. Analysis of the density of states and electronic charge density as a function of volume shows that the conduction electrons become more d like as the volume contracts. The s-d transition appears to be continuous rather than abrupt. The band structure and electronic charge densities indicate that cesium is a transition metal at high pressures. The superconductivity of cesium under high pressure is discussed in terms of the charge distribution of the conduction electrons.