From Online Dictionary of Crystallography
Revision as of 11:04, 26 February 2007 by MassimoNespolo
Groupe d'espace (Fr); Raumgruppe (Ge); Gruppo spaziale (It); 空間群 (Ja).
The symetry group of a three-dimensional crystal pattern is called its space group. In E2, the symmetry group of a two-dimensional crystal pattern is called its plane group. In E1, the symmetry group of a one-dimensional crystal pattern is called its line group.
To each crystal pattern belongs an intinite set of translations T, which are symmetry operations of that pattern. The set of all T forms a group known as the translation subgrup T of the space group G of the crystal pattern. T is an Abelian group.
Chapter 8 of the International Tables for Crystallography, Volume A