# Crystal system

(Difference between revisions)
 Revision as of 17:30, 9 November 2017 (view source)m (Tidied translations.)← Older edit Revision as of 13:06, 29 November 2017 (view source)m (Tidied translations.)Newer edit → Line 1: Line 1: - Système cristallin (''Fr''). Kristallsystem (''Ge''). Sistema cristallino (''It''). Сингония (''Ru''). 晶系(''Ja''). Sistema cristalino (''Sp''). + Système cristallin (''Fr''). Kristallsystem (''Ge''). Sistema cristallino (''It''). 晶系 (''Ja''). Сингония (''Ru''). Sistema cristalino (''Sp''). == Definition == == Definition ==

## Revision as of 13:06, 29 November 2017

Système cristallin (Fr). Kristallsystem (Ge). Sistema cristallino (It). 晶系 (Ja). Сингония (Ru). Sistema cristalino (Sp).

## Definition

A crystal-class system, or crystal system for short, contains complete geometric crystal classes of space groups. All those geometric crystal classes belong to the same crystal system which intersect exactly the same set of Bravais flocks.

## Crystal systems in two and three dimensions

In two-dimensional space there exist four crystal systems:

• oblique
• rectangular
• square
• hexagonal

In three-dimensional space there exist seven crystal systems:

• triclinic
• monoclinic
• orthorhombic
• tetragonal
• trigonal
• hexagonal
• cubic

Note that the adjective rhombohedral refers to a lattice system, not to a crystal system. Rhombohedral crystals belong to the trigonal crystal system, but trigonal crystals may belong to the rhombohedral or to the hexagonal lattice system.