# Geometric crystal class

### From Online Dictionary of Crystallography

(Difference between revisions)

m (colon instead of period) |
(Moving the note on Japanese nomenclature to the disambiguation page) |
||

Line 5: | Line 5: | ||

'''Geometric crystal classes''' (or simply 'crystal classes') classify the symmetry groups of the external shape of macroscopic crystals, namely according to the morphological symmetry. There are 10 two-dimensional geometric crystal classes and 32 three-dimensional geometric crystal classes, in one to one correspondence with the 10 and 32 types of point groups in ''E''<sup>2</sup> and ''E''<sup>3</sup>, respectively. | '''Geometric crystal classes''' (or simply 'crystal classes') classify the symmetry groups of the external shape of macroscopic crystals, namely according to the morphological symmetry. There are 10 two-dimensional geometric crystal classes and 32 three-dimensional geometric crystal classes, in one to one correspondence with the 10 and 32 types of point groups in ''E''<sup>2</sup> and ''E''<sup>3</sup>, respectively. | ||

- | |||

- | |||

- | |||

== See also == | == See also == | ||

*[[Arithmetic crystal class]] | *[[Arithmetic crystal class]] | ||

*Section 8.2.4 of ''International Tables for Crystallography, Volume A''<br> | *Section 8.2.4 of ''International Tables for Crystallography, Volume A''<br> | ||

- | |||

[[Category:Fundamental crystallography]] | [[Category:Fundamental crystallography]] |

## Revision as of 07:14, 27 April 2016

Classe cristalline géométrique (*Fr*); Geometrische Kristallklasse (*Ge*); Clase cristallina geométrica (*Sp*); Classe cristallina geometrica (*It*); 幾何的結晶類 (*Ja*).

## Definition

**Geometric crystal classes** (or simply 'crystal classes') classify the symmetry groups of the external shape of macroscopic crystals, namely according to the morphological symmetry. There are 10 two-dimensional geometric crystal classes and 32 three-dimensional geometric crystal classes, in one to one correspondence with the 10 and 32 types of point groups in *E*^{2} and *E*^{3}, respectively.

## See also

- Arithmetic crystal class
- Section 8.2.4 of
*International Tables for Crystallography, Volume A*