Term: diffusional transition
https://doi.org/10.1351/goldbook.D01717

Definition:
A transition that requires the rearrangement of atoms, ions or molecules in a manner that cannot be accomplished by a cooperative atomic displacement; it may require the movement of atoms, ions or molecules over distances significantly larger than a unit cell. Example: The transition of graphite (hexagonal sheets of three-coordinated carbon atoms) to diamond (infinite three-dimensional framework of four-coordinated carbon atoms) at high temperature and pressure.

Related Terms:
1) rearrangement (http://doi.org/10.1351/goldbook.R05194).
2) unit cell (http://doi.org/10.1351/goldbook.U06562).
3) graphite (http://doi.org/10.1351/goldbook.G02684).
4) diamond (http://doi.org/10.1351/goldbook.D01671).

Source: PAC, 1994, 66, 577. 'Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations 1994)' on page 581 (https://doi.org/10.1351/pac199466030577)

Citation: 'diffusional transition' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.D01717

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