trigonal adj : having three-fold symmetry [syn: rhombohedral]
- Italian: trigono
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 particularsThe 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.
- Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., pp. 78 - 89, ISBN 0-471-80580-7
trigonal in German: Trigonales Kristallsystem
trigonal in Basque: Kristal-sistema erronboedriko
trigonal in Korean: 삼방정계
trigonal in Latvian: Trigonālā singonija
trigonal in Norwegian: Trigonal
trigonal in Polish: Układ trygonalny
trigonal in Russian: Тригональная сингония
trigonal in Slovak: Trigonálna sústava
trigonal in Serbian: Ромбоедарска кристална система
trigonal in Serbo-Croatian: Romboedarska kristalna sistema
trigonal in Swedish: Trigonala kristallsystemet
trigonal in Ukrainian: Тригональна сингонія
trigonal in Chinese: 三方晶系