a solid figure having four plane faces. A regular tetrahedron has faces that are equilateral triangles
See also polyhedron
2.
any object shaped like a tetrahedron
Derived forms
tetrahedral (ˌtetraˈhedral)
adjective
tetrahedrally (ˌtetraˈhedrally)
adverb
Word origin
C16: from New Latin, from Late Greek tetraedron; see tetra-, -hedron
Examples of 'tetrahedra' in a sentence
tetrahedra
It comprises two concentric tetrahedra, subdivided by various symmetry planes.
Ian Stewart 2014, 'Symmetry-Breaking in a Rate Model for a Biped Locomotion Central Pattern Generator',Symmetryhttp://www.mdpi.com/2073-8994/6/1/23. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The structure contains pairs of gallium-centered tetrahedra connected through a sharedoxygen vertex.
Christopher D. DeSpain, Chunhua Hu, Robert W. Smith 2008, 'Dirubidium digallium oxide bis(orthoborate)', Acta Crystallographica Section Ehttp://scripts.iucr.org/cgi-bin/paper?S1600536808005783. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
These tetrahedra reside around a crystallographic inversion center and form 8-membered rings.
Daniel M. Seo, Paul D. Boyle, Wesley A. Henderson 2011, 'Poly[[(acetonitrile)lithium(I)]-μ3-tetrafluoridoborato]', Acta Crystallographica Section Ehttp://scripts.iucr.org/cgi-bin/paper?S1600536811012141. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Such layers are shared by common vanadate tetrahedra.
Nour El Houda Lamsakhar, Mohammed Zriouil, Abderrazzak Assani, Mohamed Saadi, LahcenEl Ammari 2018, 'Crystal structure of disilver(I) dizinc(II) iron(III) tris(orthovanadate) with analluaudite-type structure', Acta Crystallographica Section E: Crystallographic Communicationshttp://scripts.iucr.org/cgi-bin/paper?S205698901801071X. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Silicon-centered nitrogen tetrahedra form a three-dimensional network structure by sharing their corners.
Hisanori Yamane, Toshiki Nagura, Tomohiro Miyazaki 2014, 'La3Si6N11', Acta Crystallographica Section Ehttp://scripts.iucr.org/cgi-bin/paper?S1600536814009234. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Both tetrahedra show an orientation similar to that of a pair of self-dual platonic bodies.
Simon Klenk, Wolfgang Frey, Martina Bubrin, Sabine Laschat 2014, 'Tetra-μ3-iodido-tetrakis[(tri-n-butylphosphane-κP)copper(I)]', Acta Crystallographica Section Ehttp://scripts.iucr.org/cgi-bin/paper?S1600536814003390. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Trigonal prisms and tetrahedra are connected to each other by their edges.
M. Daszkiewicz, L. D. Gulay, V. Ya. Shemet, A. Pietraszko 2008, 'Dy8SnS13.61O0.39 from single-crystal data', Acta Crystallographica Section Ehttp://scripts.iucr.org/cgi-bin/paper?S1600536807063416. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
These sheets consist of 12-, six- and four-membered rings of tetrahedra in a 1:2:3 ratio.
Hexiong Yang, Robert T. Downs, Yongbo W. Yang, Warren H. Allen 2012, 'Pyrosmalite-(Fe), Fe8Si6O15(OH,Cl)10', Acta Crystallographica Section Ehttp://scripts.iucr.org/cgi-bin/paper?S1600536811052822. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Medium range structure can be characterized by the sizes of irreducible rings composed of the aluminosilica tetrahedra.
Simakin, A. G., Salova, T. P., Romero, M., Rincón, J. Ma. 2001, 'Structure of aluminosilicate melts produced from granite rocks for the manufacturingof petrurgical glass-ceramics construction materials', Materiales de Construccionhttp://materconstrucc.revistas.csic.es/index.php/materconstrucc/article/view/365/411. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)