Chapter 13.1 Noncrystallographic symmetry

Crystallography of biological macromolecules

Second Online Edition (2012)

Part 13. Molecular replacement

  1. D. M. Blow

Published Online: 14 APR 2012

DOI: 10.1107/97809553602060000839

International Tables for Crystallography

International Tables for Crystallography

How to Cite

Blow, D. M. 2012. Noncrystallographic symmetry. International Tables for Crystallography. F:13:13.1:333–339.

Author Information

  1. Biophysics Group, Blackett Laboratory, Imperial College of Science, Technology & Medicine, London SW7 2BW, England

Publication History

  1. Published Online: 14 APR 2012



This chapter provides an introduction to noncrystallographic symmetry. Topics covered include: the definition of noncrystallographic symmetry; the use of the Patterson function to interpret noncrystallographic symmetry; the interpretation of generalized noncrystallographic symmetry where the molecular structure is partially known; and the power of noncrystallographic symmetry in structure analysis.


  • Patterson functions;
  • cross‐rotation function;
  • cross‐translation function and noncrystallographic symmetry;
  • molecular replacement;
  • noncrystallographic symmetry;
  • rotation functions;
  • structure determination;
  • translation functions