symmetry breaking

in crystals, in polymer crystals
https://doi.org/10.1351/goldbook.14227
Vanishing, in a specific crystal polymorph, of selected symmetry elements present in other crystal polymorphs, or in selected minimum energy conformations of isolated molecules of a given substance.
Notes:
  1. The symmetry elements that vanish are frequently intramolecular. Symmetry breaking in polymers in such cases leads to deviations from the ideal crystalline chain conformation and from the equivalence postulate.
  2. Crystal polymorphs affected by symmetry breaking are usually stable at low temperature under conditions that optimize packing energy.
Source:
PAC, 2011, 83, 1831. (Definitions of terms relating to crystalline polymers (IUPAC Recommendations 2011)) on page 1847 [Terms] [Paper]
Citation: 'symmetry breaking' 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.14227 RIS BibTex EndNote
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