Lattice system
From Online Dictionary of Crystallography
Revision as of 15:38, 23 February 2007 by MassimoNespolo (talk | contribs)
Système réticulaire (Fr). Sistema reticolare (It)
Contents
Definition
A lattice system of space groups contains complete Bravais flocks. All those Bravais flocks which intersect exactly the same set of geometric crystal classes belong to the same lattice system.
Alternative definition
A lattice system of space groups contains complete Bravais flocks. All those Bravais flocks belong to the same lattice system for which the Bravais classes belong to the same (holohedral) geometric crystal class.
Lattice systems in two and three dimensions
In the two-dimensional space there exist four lattice systems:
- monoclinic
- orthorhombic
- tetragonal
- hexagonal
In the three-dimensional space there exist seven lattice systems:
- triclinic
- monoclinic
- orthorhombic
- tetragonal
- rhombohedral
- hexagonal
- cubic
Note that the adjective trigonal refers to a crystal system, not to a lattice system. Rhombohedral crystals belong to the trigonal crystal system, but trigonal crystals may belong to the rhombohedral or to the hexagonal lattice system.
See also
Section 8.2.8 in of International Tables of Crystallography, Volume A