New results on old problems: The use of single-crystals in high-pressure structural studies

Single-crystal X-ray diffraction techniques have been applied to a number of outstanding structural problems in elemental metals. Cs-III, Rb-III and Ga-II are shown to be members of a new class of modulated elemental structure containing different stackings of 8- and 10-atom layers; the interaction of the host and guest components in the incommensurate composite structure of Bi-III is found to induce modulations of the basic host and guest structures; and Te-III is shown to have a body-centred monoclinic structure modulated by an incommensurate displacement wave.