https://doi.org/10.1351/goldbook.P04748
A reversible transition of a solid crystalline phase at a certain temperature and pressure (the inversion point) to another phase of the same chemical composition with a different crystal structure.
Note: In a liquid-crystal transition, this term refers to phase changes in the smectic state or columnar discotic state.
Examples:
- The transitions of $\ce{SiO2}$ (quartz-type) at \(1143\ \rm{K}\) to $\ce{SiO2}$ (tridymite-type), and at \(1743\ \rm{K}\) to $\ce{SiO2}$ (cristobalite-type).
- The transition of $\ce{\upbeta\mbox{-}AgI}$ (wurtzite-type structure) to $\ce{\upalpha\mbox{-}AgI}$ (body-centred-cubic structure) at \(418\ \rm{K}\). Synonymous with 'enantiotropic transition'.