Details

Autor(en) / Beteiligte

• Nespolo, Massimo
• Aroyo, Mois I.

Titel

The crystallographic chameleon: when space groups change skin

Ist Teil von

• Acta crystallographica. Section A, Foundations and advances, 2016-09, Vol.72 (5), p.523-538

Ort / Verlag

5 Abbey Square, Chester, Cheshire CH1 2HU, England: International Union of Crystallography

Erscheinungsjahr

2016

Quelle

Wiley Online Library

Beschreibungen/Notizen

• Volume A of International Tables for Crystallography is the reference for space‐group information. However, the content is not exhaustive because for many space groups a variety of settings may be chosen but not all of them are described in detail or even fully listed. The use of alternative settings may seem an unnecessary complication when the purpose is just to describe a crystal structure; however, these are of the utmost importance for a number of tasks, such as the investigation of structure relations between polymorphs or derivative structures, the study of pseudo‐symmetry and its potential consequences, and the analysis of the common substructure of twins. The aim of the article is twofold: (i) to present a guide to expressing the symmetry operations, the Hermann–Mauguin symbols and the Wyckoff positions of a space group in an alternative setting, and (ii) to point to alternative settings of space groups of possible practical applications and not listed in Volume A of International Tables for Crystallography. Alternative settings of space groups are explored: what they are, why they can be useful and how to obtain them.