Rod group

{
  "id": "MLC-T-CHM-010397",
  "term": "Rod group",
  "field": "Chemistry",
  "definition": "A symmetry group for atoms arranged in three dimensions but repeating regularly along only one direction, which is how the symmetry of an isolated polymer chain is described. Its operations combine translation along the chain axis with rotations, mirror planes and screw or helical motions. The crystallographic version limits screw axes to twofold, threefold, fourfold and sixfold and yields 75 rod groups, while an isolated chain can have any helical symmetry.",
  "synonyms": [
    "line repetition group"
  ],
  "subject": "Polymer",
  "see_also": [
    "ideal crystalline chain conformation"
  ],
  "references": [
    "PAC, 2011, 83, 1831. 'Definitions of terms relating to crystalline polymers (IUPAC Recommendations 2011)' on page 1842 (https://doi.org/10.1351/PAC-REC-10-11-13)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/rod-group/"
}