Chapter 3.8 Classification and use of symmetry data

Definition and exchange of crystallographic data

First Online Edition (2006)

Part 3. CIF data definition and classification

  1. I. D. Brown

Published Online: 1 JAN 2006

DOI: 10.1107/97809553602060000740

International Tables for Crystallography

International Tables for Crystallography

How to Cite

Brown, I. D. 2006. Classification and use of symmetry data. International Tables for Crystallography. G:3:3.8:206–208.

Author Information

  1. Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario, Canada L8S 4M1

Publication History

  1. Published Online: 1 JAN 2006



The symmetry CIF dictionary (symCIF) is a small dictionary of data items that refine and extend the definition of symmetry beyond the pragmatic requirements of the core CIF dictionary. The aims are to reflect the current state of space‐group theory and to provide rigorous definitions suitable for use in future applications such as software representations of the symmetry properties of space groups, and inclusion of higher‐dimensional symmetry in CIFs reporting quasicrystal, magnetic and modulated structures.


  • symCIF dictionary;
  • symmetry Crystallographic Information File;
  • Hall space‐group symbols;
  • Hermann–Mauguin symbols;
  • multiplicity;
  • origin choice;
  • point groups;
  • Schoenflies symbols;
  • space‐group information;
  • space groups;
  • special positions;
  • symmetry