Nomenclature of magnetic, incommensurate, composition-changed morphotropic, polytype, transient-structural and quasicrystalline phases undergoing phase transitions. II. Report of an IUCr Working Group on Phase Transition Nomenclature

The six-field notation recommended by the Commission on Crystallographic Nomenclature [Tolédano et al. (1998). Acta Cryst. A54, 1028-1033], for each phase formed in any sequence of structural transitions as the result of a change in temperature and/or pressure, is shown to be quite general and applicable to all transitions in the solid state. Six additional representative classes of phase transition are considered in detail, with illustrative examples provided of the nomenclature applicable to each category.