trigonal system

trigonal system

also called  Rhombohedral System, 

      one of the structural categories to which crystalline solids can be assigned. The trigonal system is sometimes considered to be a subdivision of the hexagonal system.

      Components of crystals in the trigonal system, like those of the hexagonal system, are located by reference to four axes—three of equal length with 120° intersections and one perpendicular to the plane of the other three. The trigonal unit cell is distinguished by the presence of a single line called an axis of three-fold symmetry about which the cell can be rotated by 120° to produce a face indistinguishable from the face presented in the starting position. Selenium and other elements may crystallize in trigonal form.

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Universalium. 2010.

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  • trigonal system — trigoninė sistema statusas T sritis chemija apibrėžtis Kristalografinė sistema, kuriai būdinga trečiosios eilės simetrijos ašis. atitikmenys: angl. trigonal system rus. ромбоэдрическая система; тригональная система ryšiai: sinonimas – romboedrinė …   Chemijos terminų aiškinamasis žodynas

  • trigonal system — noun : a crystal system that is characterized by three equal and equally inclined axes and that is commonly held to be a division of the hexagonal system …   Useful english dictionary

  • trigonal crystal system — trigoninė kristalografinė sistema statusas T sritis fizika atitikmenys: angl. trigonal crystal system; trigonal crystallographic system vok. trigonales Kristallsystem, n rus. ромбоэдрическая кристаллографическая система, f; тригональная… …   Fizikos terminų žodynas

  • trigonal crystallographic system — trigoninė kristalografinė sistema statusas T sritis fizika atitikmenys: angl. trigonal crystal system; trigonal crystallographic system vok. trigonales Kristallsystem, n rus. ромбоэдрическая кристаллографическая система, f; тригональная… …   Fizikos terminų žodynas

  • Trigonal trisoctahedron — Trisoctahedron Tris*oc ta*he dron, n. [Gr. ? thrice + FE. octahedron.] (Crystallog.) A solid of the isometric system bounded by twenty four equal faces, three corresponding to each face of an octahedron. [1913 Webster] {Tetragonal trisoctahedron} …   The Collaborative International Dictionary of English

  • trigonal — adjective Date: 1878 of, relating to, or being the division of the hexagonal crystal system or the forms belonging to it characterized by a vertical axis of threefold symmetry • trigonally adverb …   New Collegiate Dictionary

  • trigonal — [ trɪg(ə)n(ə)l] adjective 1》 triangular.     ↘chiefly Biology triangular in cross section. 2》 denoting a crystal system with three equal axes separated by equal angles that are not right angles. Derivatives trigonally adverb …   English new terms dictionary

  • crystal system — noun : any of the six or sometimes seven main groups into which crystals are commonly classified according to the relative lengths and inclinations of their axes or according to their respective symmetries see hexagonal system, isometric system,… …   Useful english dictionary

  • Crystal system — Diamond crystal structure consists of face centered cubic lattice. In crystallography, the terms crystal system, crystal family, and lattice system each refer to one of several classes of space groups, lattices, point groups, or crystals.… …   Wikipedia

  • système trigonal — trigoninė kristalografinė sistema statusas T sritis fizika atitikmenys: angl. trigonal crystal system; trigonal crystallographic system vok. trigonales Kristallsystem, n rus. ромбоэдрическая кристаллографическая система, f; тригональная… …   Fizikos terminų žodynas

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