|
INTERNATIONAL TABLES for CRYSTALLOGRAPHY |
Volume G |
Definition and Exchange of Crystallographic Data |
Definition:
Superspace-group symbol as given by de Wolff, Janssen & Janner
(1981). Valid only for one-dimensional modulated structures.
The symbol is divided into three parts separated by colons ':':
the superspace lattice symbol, the Hermann-Mauguin space-group
symbol of the reference structure and the phase shift (or
internal translation) associated with each component of the
space group. Each component of the space-group name is separated
by a space. Subscripts should appear without special symbols and
bars should be given as negative signs. The phase shifts are
also separated by a space. For composites described in a single
data block, the superspace group describes the symmetry of the
whole structure. The symmetry of each subsystem can be derived
using the appropriate W matrices.
Ref: Wolff, P. M. de, Janssen, T. & Janner, A. (1981).
Acta Cryst. A37, 625-636.
Example:| 'P:P c m n:s s -1' |
Type: char
Category: space_group
Copyright © 2005 International Union of Crystallography