Term: chain-orientational disorder https://doi.org/10.1351/goldbook.C00957 Definition: structural disorder resulting from the statistical coexistence within the crystals of identical chains with opposite orientations. A typical example is provided by the up-down statistical coexistence of anticlined chains in the same crystal structure. Related Terms: 1) structural disorder (http://doi.org/10.1351/goldbook.S06060). Source: Purple Book, 1st ed., p. 80 (http://old.iupac.org/publications/books/author/metanomski.html) Citation: 'chain-orientational disorder' 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.C00957 License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.