14260 IUPAC Gold Book - twinned polymer crystal 10.1351/goldbook.14260 14260 current 1 Polymer crystal in which two or more single crystalline domains of the same crystal polymorph, with different lattice orientations, coexist. Some of the lattice directions, very often the chain axis directions, remain parallel in the different domains of twinned crystals. The lattice orientations in the different domains of twinned crystals are generally symmetry-related. crystal polymorph https://goldbook.iupac.org//terms/view/14219 polymer single crystal https://goldbook.iupac.org//terms/view/14255 PAC, 2011, 83, 1831. 'Definitions of terms relating to crystalline polymers (IUPAC Recommendations 2011)' on page 1859 (https://doi.org/10.1351/PAC-REC-10-11-13) https://goldbook.iupac.org/terms/view/14260/html https://goldbook.iupac.org/terms/view/14260/json https://goldbook.iupac.org/terms/view/14260/plain Citation: 'twinned polymer crystal' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.14260 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. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . 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. 2026-06-29T00:19:38+00:00