# Cylindrical system

### From Online Dictionary of Crystallography

Système cylindrique (*Fr*) Sistema cylindrico (*It*).

## Definition

The cylindrical system contains non-crystallographic point groups with one axis of revolution (or isotropy axis). There are five groups in the spherical system:

Hermann-Mauguin symbol | Short Hermann-Mauguin symbol | Schönfliess symbol | order of the group | general form |
---|---|---|---|---|

rotating cone | ||||

rotating finite cylinder | ||||

finite cylinder submitted to equal and opposite torques |
||||

stationary cone | ||||

stationary finite cylinder |

Note that represents the symmetry of a force, or of an electric field and that represents the symmetry of a magnetic field (Curie 1894), while represents the symmetry of a uniaxial compression.

## History

The groups containing isotropy axes were introduced by P. Curie (1859-1906) in order to describe the symmetry of
physical systems (Curie P. (1884). *Sur les questions d'ordre: répétitions. Bull. Soc. Fr. Minéral.*, **7**, 89-110; Curie P. (1894). *Sur la symétrie dans les phénomènes physiques, symétrie d’un champ électrique et d’un champ magnétique. J. Phys. (Paris)*, **3**, 393-415.).

## See also

Curie laws

spherical system

Section 10.1.4 of *International Tables of Crystallography, Volume A*

Section 1.1.4 of *International Tables of Crystallography, Volume D*