# Dictionary Definition

rhombohedral adj : having three-fold symmetry
[syn: trigonal]

# User Contributed Dictionary

## English

### Adjective

rhombohedral### See also

# Extensive Definition

In crystallography, the
rhombohedral (or trigonal) crystal
system is one of the seven lattice
point groups, named after the two-dimensional rhombus. A crystal system is described by
three basis vectors.
In the rhombohedral system, the crystal is described by vectors of
equal
length, of which all
three are not mutually orthogonal. The rhombohedral
system can be thought of as the cubic system
stretched diagonal
along a body. a = b = c; \alpha = \beta = \gamma \neq 90^\circ. In
some classification schemes, the rhombohedral system is grouped
into a larger hexagonal
system.

There exists only one rhombohedral Bravais
lattice.

## List of particulars

The point groups which fall under this crystal system are listed below, followed by their representations in international notation (Hermann-Mauguin notation) and Schoenflies notation, and example crystals.## See also

## References

- Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., pp. 78 - 89, ISBN 0-471-80580-7

rhombohedral in German: Trigonales
Kristallsystem

rhombohedral in Basque: Kristal-sistema
erronboedriko

rhombohedral in Korean: 삼방정계

rhombohedral in Latvian: Trigonālā
singonija

rhombohedral in Norwegian: Trigonal

rhombohedral in Polish: Układ trygonalny

rhombohedral in Russian: Тригональная
сингония

rhombohedral in Slovak: Trigonálna sústava

rhombohedral in Serbian: Ромбоедарска кристална
система

rhombohedral in Serbo-Croatian: Romboedarska
kristalna sistema

rhombohedral in Swedish: Trigonala
kristallsystemet

rhombohedral in Ukrainian: Тригональна
сингонія

rhombohedral in Chinese: 三方晶系