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Orthogonal projections in A₇ Coxeter plane
7-simplex	Cantellated 7-simplex	Bicantellated 7-simplex	Tricantellated 7-simplex
Birectified 7-simplex	Cantitruncated 7-simplex	Bicantitruncated 7-simplex	Tricantitruncated 7-simplex

In seven-dimensional geometry, a cantellated 7-simplex is a convex uniform 7-polytope, being a cantellation of the regular 7-simplex.

There are unique 6 degrees of cantellation for the 7-simplex, including truncations.

Cantellated 7-simplex

Cantellated 7-simplex
Type	uniform 7-polytope
Schläfli symbol	rr{3,3,3,3,3,3} or $r\left\{{\begin{array}{l}3,3,3,3,3\\3\end{array}}\right\}$
Coxeter-Dynkin diagram	or
6-faces
5-faces
4-faces
Cells
Faces
Edges	1008
Vertices	168
Vertex figure	5-simplex prism
Coxeter groups	A₇, [3,3,3,3,3,3]
Properties	convex

Alternate names

Small rhombated octaexon (acronym: saro) (Jonathan Bowers)^[1]

Coordinates

The vertices of the cantellated 7-simplex can be most simply positioned in 8-space as permutations of (0,0,0,0,0,1,1,2). This construction is based on facets of the cantellated 8-orthoplex.

Images

orthographic projections
A_k Coxeter plane	A₇	A₆	A₅
Graph
Dihedral symmetry	[8]	[7]	[6]
A_k Coxeter plane	A₄	A₃	A₂
Graph
Dihedral symmetry	[5]	[4]	[3]

Bicantellated 7-simplex

Bicantellated 7-simplex
Type	uniform 7-polytope
Schläfli symbol	r2r{3,3,3,3,3,3} or $r\left\{{\begin{array}{l}3,3,3,3\\3,3\end{array}}\right\}$
Coxeter-Dynkin diagrams	or
6-faces
5-faces
4-faces
Cells
Faces
Edges	2520
Vertices	420
Vertex figure
Coxeter groups	A₇, [3,3,3,3,3,3]
Properties	convex

Alternate names

Small birhombated octaexon (acronym: sabro) (Jonathan Bowers)^[2]

Coordinates

The vertices of the bicantellated 7-simplex can be most simply positioned in 8-space as permutations of (0,0,0,0,1,1,2,2). This construction is based on facets of the bicantellated 8-orthoplex.

Images

orthographic projections
A_k Coxeter plane	A₇	A₆	A₅
Graph
Dihedral symmetry	[8]	[7]	[6]
A_k Coxeter plane	A₄	A₃	A₂
Graph
Dihedral symmetry	[5]	[4]	[3]

Tricantellated 7-simplex

Tricantellated 7-simplex
Type	uniform 7-polytope
Schläfli symbol	r3r{3,3,3,3,3,3} or $r\left\{{\begin{array}{l}3,3,3\\3,3,3\end{array}}\right\}$
Coxeter-Dynkin diagrams	or
6-faces
5-faces
4-faces
Cells
Faces
Edges	3360
Vertices	560
Vertex figure
Coxeter groups	A₇, [3,3,3,3,3,3]
Properties	convex

Alternate names

Small trirhombihexadecaexon (stiroh) (Jonathan Bowers)^[3]

Coordinates

The vertices of the tricantellated 7-simplex can be most simply positioned in 8-space as permutations of (0,0,0,1,1,2,2,2). This construction is based on facets of the tricantellated 8-orthoplex.

Images

orthographic projections
A_k Coxeter plane	A₇	A₆	A₅
Graph
Dihedral symmetry	[8]	[7]	[6]
A_k Coxeter plane	A₄	A₃	A₂
Graph
Dihedral symmetry	[5]	[4]	[3]

Cantitruncated 7-simplex

Cantitruncated 7-simplex
Type	uniform 7-polytope
Schläfli symbol	tr{3,3,3,3,3,3} or $t\left\{{\begin{array}{l}3,3,3,3,3\\3\end{array}}\right\}$
Coxeter-Dynkin diagrams
6-faces
5-faces
4-faces
Cells
Faces
Edges	1176
Vertices	336
Vertex figure
Coxeter groups	A₇, [3,3,3,3,3,3]
Properties	convex

Alternate names

Great rhombated octaexon (acronym: garo) (Jonathan Bowers)^[4]

Coordinates

The vertices of the cantitruncated 7-simplex can be most simply positioned in 8-space as permutations of (0,0,0,0,0,1,2,3). This construction is based on facets of the cantitruncated 8-orthoplex.

Images

orthographic projections
A_k Coxeter plane	A₇	A₆	A₅
Graph
Dihedral symmetry	[8]	[7]	[6]
A_k Coxeter plane	A₄	A₃	A₂
Graph
Dihedral symmetry	[5]	[4]	[3]

Bicantitruncated 7-simplex

Bicantitruncated 7-simplex
Type	uniform 7-polytope
Schläfli symbol	t2r{3,3,3,3,3,3} or $t\left\{{\begin{array}{l}3,3,3,3\\3,3\end{array}}\right\}$
Coxeter-Dynkin diagrams	or
6-faces
5-faces
4-faces
Cells
Faces
Edges	2940
Vertices	840
Vertex figure
Coxeter groups	A₇, [3,3,3,3,3,3]
Properties	convex

Alternate names

Great birhombated octaexon (acronym: gabro) (Jonathan Bowers)^[5]

Coordinates

The vertices of the bicantitruncated 7-simplex can be most simply positioned in 8-space as permutations of (0,0,0,0,1,2,3,3). This construction is based on facets of the bicantitruncated 8-orthoplex.

Images

orthographic projections
A_k Coxeter plane	A₇	A₆	A₅
Graph
Dihedral symmetry	[8]	[7]	[6]
A_k Coxeter plane	A₄	A₃	A₂
Graph
Dihedral symmetry	[5]	[4]	[3]

Tricantitruncated 7-simplex

Tricantitruncated 7-simplex
Type	uniform 7-polytope
Schläfli symbol	t3r{3,3,3,3,3,3} or $t\left\{{\begin{array}{l}3,3,3\\3,3,3\end{array}}\right\}$
Coxeter-Dynkin diagrams	or
6-faces
5-faces
4-faces
Cells
Faces
Edges	3920
Vertices	1120
Vertex figure
Coxeter groups	A₇, [3,3,3,3,3,3]
Properties	convex

Alternate names

Great trirhombihexadecaexon (acronym: gatroh) (Jonathan Bowers)^[6]

Coordinates

The vertices of the tricantitruncated 7-simplex can be most simply positioned in 8-space as permutations of (0,0,0,1,2,3,4,4). This construction is based on facets of the tricantitruncated 8-orthoplex.

Images

orthographic projections
A_k Coxeter plane	A₇	A₆	A₅
Graph
Dihedral symmetry	[8]	[[7]]	[6]
A_k Coxeter plane	A₄	A₃	A₂
Graph
Dihedral symmetry	[[5]]	[4]	[[3]]

Related polytopes

This polytope is one of 71 uniform 7-polytopes with A₇ symmetry.

Notes

^ Klitizing, (x3o3x3o3o3o3o - saro)
^ Klitizing, (o3x3o3x3o3o3o - sabro)
^ Klitizing, (o3o3x3o3x3o3o - stiroh)
^ Klitizing, (x3x3x3o3o3o3o - garo)
^ Klitizing, (o3x3x3x3o3o3o - gabro)
^ Klitizing, (o3o3x3x3x3o3o - gatroh)

References

H.S.M. Coxeter:
- H.S.M. Coxeter, Regular Polytopes, 3rd Edition, Dover New York, 1973
- Kaleidoscopes: Selected Writings of H.S.M. Coxeter, edited by F. Arthur Sherk, Peter McMullen, Anthony C. Thompson, Asia Ivic Weiss, Wiley-Interscience Publication, 1995, ISBN 978-0-471-01003-6 [1]
  - (Paper 22) H.S.M. Coxeter, Regular and Semi Regular Polytopes I, [Math. Zeit. 46 (1940) 380-407, MR 2,10]
  - (Paper 23) H.S.M. Coxeter, Regular and Semi-Regular Polytopes II, [Math. Zeit. 188 (1985) 559-591]
  - (Paper 24) H.S.M. Coxeter, Regular and Semi-Regular Polytopes III, [Math. Zeit. 200 (1988) 3-45]
Norman Johnson Uniform Polytopes, Manuscript (1991)
- N.W. Johnson: The Theory of Uniform Polytopes and Honeycombs, Ph.D.
Klitzing, Richard. "7D uniform polytopes (polyexa)". x3o3x3o3o3o3o - saro, o3x3o3x3o3o3o - sabro, o3o3x3o3x3o3o - stiroh, x3x3x3o3o3o3o - garo, o3x3x3x3o3o3o - gabro, o3o3x3x3x3o3o - gatroh

External links

v t e Fundamental convex regular and uniform polytopes in dimensions 2–10
Family	A_n	B_n	I₂(p) / D_n	E₆ / E₇ / E₈ / F₄ / G₂	H_n
Regular polygon	Triangle	Square	p-gon	Hexagon	Pentagon
Uniform polyhedron	Tetrahedron	Octahedron • Cube	Demicube		Dodecahedron • Icosahedron
Uniform polychoron	Pentachoron	16-cell • Tesseract	Demitesseract	24-cell	120-cell • 600-cell
Uniform 5-polytope	5-simplex	5-orthoplex • 5-cube	5-demicube
Uniform 6-polytope	6-simplex	6-orthoplex • 6-cube	6-demicube	1₂₂ • 2₂₁
Uniform 7-polytope	7-simplex	7-orthoplex • 7-cube	7-demicube	1₃₂ • 2₃₁ • 3₂₁
Uniform 8-polytope	8-simplex	8-orthoplex • 8-cube	8-demicube	1₄₂ • 2₄₁ • 4₂₁
Uniform 9-polytope	9-simplex	9-orthoplex • 9-cube	9-demicube
Uniform 10-polytope	10-simplex	10-orthoplex • 10-cube	10-demicube
Uniform n-polytope	n-simplex	n-orthoplex • n-cube	n-demicube	1_k2 • 2_k1 • k₂₁	n-pentagonal polytope
Topics: Polytope families • Regular polytope • List of regular polytopes and compounds