Line repetition groups

{
  "id": "MLC-T-CHM-006607",
  "term": "Line repetition groups",
  "field": "Chemistry",
  "definition": "The set of one-dimensional space groups that describe the possible symmetry operations for a linear object with periodic repetition along a line, such as an isolated polymer chain. These groups combine a translation along the chain axis with other symmetry elements like rotation about the axis (screw axis) or reflection through planes containing the axis. The symmetry of a helical polymer chain, for example, is described by one of these line groups.",
  "subject": "Polymer",
  "see_also": [
    "helix",
    "inversion",
    "linear polymer",
    "identity period"
  ],
  "references": [
    "Purple Book, 1st ed., p. 79 (http://old.iupac.org/publications/books/author/metanomski.html)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/line-repetition-groups/"
}