Identity period

{
  "id": "MLC-T-CHM-005576",
  "term": "Identity period",
  "field": "Chemistry",
  "definition": "The smallest repeating distance along the axis of a polymer chain in a crystalline state, corresponding to the length of one repeating unit or a multiple thereof. This parameter is determined by X-ray diffraction and reflects the specific helical or planar zigzag conformation adopted by the polymer chain within the crystal lattice. It is a fundamental characteristic of polymer crystallinity.",
  "synonyms": [
    "chain repeating distance",
    "repeating distance",
    "chain identity period"
  ],
  "subject": "Polymer",
  "references": [
    "Purple Book, 1st ed., p. 77 (http://old.iupac.org/publications/books/author/metanomski.html)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/identity-period/"
}