Calculated properties of high-pressure phases of 'simple metals'

X-ray diffraction experiments carried out on alkali metals under high pressure have provided new insight into pressure-induced structural transformations. New structures have been identified, and some of these have surprising similarities, such as low coordination numbers. The present ab initio calculations of electronic and structural properties provide theoretical support for the analysis of these experiments, and may also serve to predict new properties, such as superconductivity, of the materials when exposed to high pressures.