Truncated 8-simplexes
In eight-dimensional geometry, a truncated 8-simplex is a convex uniform 8-polytope, being a truncation of the regular 8-simplex.
![]() 8-simplex  | 
![]() Truncated 8-simplex  | 
![]() Rectified 8-simplex  | 
![]() Quadritruncated 8-simplex  | 
![]() Tritruncated 8-simplex  | 
![]() Bitruncated 8-simplex  | 
| Orthogonal projections in A8 Coxeter plane | ||
|---|---|---|
There are four unique degrees of truncation. Vertices of the truncation 8-simplex are located as pairs on the edge of the 8-simplex. Vertices of the bitruncated 8-simplex are located on the triangular faces of the 8-simplex. Vertices of the tritruncated 8-simplex are located inside the tetrahedral cells of the 8-simplex.
Truncated 8-simplex
    
| Truncated 8-simplex | |
|---|---|
| Type | uniform 8-polytope | 
| Schläfli symbol | t{37} | 
| Coxeter-Dynkin diagrams | |
| 7-faces | |
| 6-faces | |
| 5-faces | |
| 4-faces | |
| Cells | |
| Faces | |
| Edges | 288 | 
| Vertices | 72 | 
| Vertex figure | ( )v{3,3,3,3,3} | 
| Coxeter group | A8, [37], order 362880 | 
| Properties | convex | 
Alternate names
    
- Truncated enneazetton (Acronym: tene) (Jonathan Bowers)[1]
 
Coordinates
    
The Cartesian coordinates of the vertices of the truncated 8-simplex can be most simply positioned in 9-space as permutations of (0,0,0,0,0,0,0,1,2). This construction is based on facets of the truncated 9-orthoplex.
Images
    
| Ak Coxeter plane | A8 | A7 | A6 | A5 | 
|---|---|---|---|---|
| Graph | ![]()  | 
![]()  | 
![]()  | 
![]()  | 
| Dihedral symmetry | [9] | [8] | [7] | [6] | 
| Ak Coxeter plane | A4 | A3 | A2 | |
| Graph | ![]()  | 
![]()  | 
![]()  | |
| Dihedral symmetry | [5] | [4] | [3] | 
Bitruncated 8-simplex
    
| Bitruncated 8-simplex | |
|---|---|
| Type | uniform 8-polytope | 
| Schläfli symbol | 2t{37} | 
| Coxeter-Dynkin diagrams | |
| 7-faces | |
| 6-faces | |
| 5-faces | |
| 4-faces | |
| Cells | |
| Faces | |
| Edges | 1008 | 
| Vertices | 252 | 
| Vertex figure | { }v{3,3,3,3} | 
| Coxeter group | A8, [37], order 362880 | 
| Properties | convex | 
Alternate names
    
- Bitruncated enneazetton (Acronym: batene) (Jonathan Bowers)[2]
 
Coordinates
    
The Cartesian coordinates of the vertices of the bitruncated 8-simplex can be most simply positioned in 9-space as permutations of (0,0,0,0,0,0,1,2,2). This construction is based on facets of the bitruncated 9-orthoplex.
Images
    
| Ak Coxeter plane | A8 | A7 | A6 | A5 | 
|---|---|---|---|---|
| Graph | ![]()  | 
![]()  | 
![]()  | 
![]()  | 
| Dihedral symmetry | [9] | [8] | [7] | [6] | 
| Ak Coxeter plane | A4 | A3 | A2 | |
| Graph | ![]()  | 
![]()  | 
![]()  | |
| Dihedral symmetry | [5] | [4] | [3] | 
Tritruncated 8-simplex
    
| tritruncated 8-simplex | |
|---|---|
| Type | uniform 8-polytope | 
| Schläfli symbol | 3t{37} | 
| Coxeter-Dynkin diagrams | |
| 7-faces | |
| 6-faces | |
| 5-faces | |
| 4-faces | |
| Cells | |
| Faces | |
| Edges | 2016 | 
| Vertices | 504 | 
| Vertex figure | {3}v{3,3,3} | 
| Coxeter group | A8, [37], order 362880 | 
| Properties | convex | 
Alternate names
    
- Tritruncated enneazetton (Acronym: tatene) (Jonathan Bowers)[3]
 
Coordinates
    
The Cartesian coordinates of the vertices of the tritruncated 8-simplex can be most simply positioned in 9-space as permutations of (0,0,0,0,0,1,2,2,2). This construction is based on facets of the tritruncated 9-orthoplex.
Images
    
| Ak Coxeter plane | A8 | A7 | A6 | A5 | 
|---|---|---|---|---|
| Graph | ![]()  | 
![]()  | 
![]()  | 
![]()  | 
| Dihedral symmetry | [9] | [8] | [7] | [6] | 
| Ak Coxeter plane | A4 | A3 | A2 | |
| Graph | ![]()  | 
![]()  | 
![]()  | |
| Dihedral symmetry | [5] | [4] | [3] | 
Quadritruncated 8-simplex
    
| Quadritruncated 8-simplex | |
|---|---|
| Type | uniform 8-polytope | 
| Schläfli symbol | 4t{37} | 
| Coxeter-Dynkin diagrams | or  | 
| 6-faces | 18 3t{3,3,3,3,3,3} | 
| 7-faces | |
| 5-faces | |
| 4-faces | |
| Cells | |
| Faces | |
| Edges | 2520 | 
| Vertices | 630 | 
| Vertex figure | ![]() {3,3}v{3,3}  | 
| Coxeter group | A8, [[37]], order 725760 | 
| Properties | convex, isotopic | 
The quadritruncated 8-simplex an isotopic polytope, constructed from 18 tritruncated 7-simplex facets.
Alternate names
    
- Octadecazetton (18-facetted 8-polytope) (Acronym: be) (Jonathan Bowers)[4]
 
Coordinates
    
The Cartesian coordinates of the vertices of the quadritruncated 8-simplex can be most simply positioned in 9-space as permutations of (0,0,0,0,1,2,2,2,2). This construction is based on facets of the quadritruncated 9-orthoplex.
Images
    
| Ak Coxeter plane | A8 | A7 | A6 | A5 | 
|---|---|---|---|---|
| Graph | ![]()  | 
![]()  | 
![]()  | 
![]()  | 
| Dihedral symmetry | [[9]] = [18] | [8] | [[7]] = [14] | [6] | 
| Ak Coxeter plane | A4 | A3 | A2 | |
| Graph | ![]()  | 
![]()  | 
![]()  | |
| Dihedral symmetry | [[5]] = [10] | [4] | [[3]] = [6] | 
Related polytopes
    
| Dim. | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 
|---|---|---|---|---|---|---|---|
| Name Coxeter  | 
Hexagon t{3} = {6}  | 
Octahedron r{3,3} = {31,1} = {3,4}  | 
Decachoron 2t{33}  | 
Dodecateron 2r{34} = {32,2}  | 
Tetradecapeton 3t{35}  | 
Hexadecaexon 3r{36} = {33,3}  | 
Octadecazetton 4t{37}  | 
| Images | ![]()  | 
![]() ![]()  | 
![]() ![]()  | 
![]() ![]()  | 
![]() ![]()  | 
![]() ![]()  | 
![]() ![]()  | 
| Vertex figure | ( )∨( ) | ![]() { }×{ }  | 
![]() { }∨{ }  | 
![]() {3}×{3}  | 
![]() {3}∨{3}  | 
{3,3}×{3,3} | ![]() {3,3}∨{3,3}  | 
| Facets | {3}  | 
t{3,3}  | 
r{3,3,3}  | 
2t{3,3,3,3}  | 
2r{3,3,3,3,3}  | 
3t{3,3,3,3,3,3}   | |
| As intersecting dual simplexes  | 
![]()  | 
![]()  | 
![]() ![]()  | 
Related polytopes
    
This polytope is one of 135 uniform 8-polytopes with A8 symmetry.
| A8 polytopes | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
t0  | 
t1  | 
t2  | 
t3  | 
t01  | 
t02  | 
t12  | 
t03  | 
t13  | 
t23  | 
t04  | 
t14  | 
t24  | 
t34  | 
t05  | 
t15  | 
t25  | 
t06  | 
t16  | 
t07  | 
t012  | 
t013  | 
t023  | 
t123  | 
t014  | 
t024  | 
t124  | 
t034  | 
t134  | 
t234  | 
t015  | 
t025  | 
t125  | 
t035  | 
t135  | 
t235  | 
t045  | 
t145  | 
t016  | 
t026  | 
t126  | 
t036  | 
t136  | 
t046  | 
t056  | 
t017  | 
t027  | 
t037  | 
t0123  | 
t0124  | 
t0134  | 
t0234  | 
t1234  | 
t0125  | 
t0135  | 
t0235  | 
t1235  | 
t0145  | 
t0245  | 
t1245  | 
t0345  | 
t1345  | 
t2345  | 
t0126  | 
t0136  | 
t0236  | 
t1236  | 
t0146  | 
t0246  | 
t1246  | 
t0346  | 
t1346  | 
t0156  | 
t0256  | 
t1256  | 
t0356  | 
t0456  | 
t0127  | 
t0137  | 
t0237  | 
t0147  | 
t0247  | 
t0347  | 
t0157  | 
t0257  | 
t0167  | 
t01234  | 
t01235  | 
t01245  | 
t01345  | 
t02345  | 
t12345  | 
t01236  | 
t01246  | 
t01346  | 
t02346  | 
t12346  | 
t01256  | 
t01356  | 
t02356  | 
t12356  | 
t01456  | 
t02456  | 
t03456  | 
t01237  | 
t01247  | 
t01347  | 
t02347  | 
t01257  | 
t01357  | 
t02357  | 
t01457  | 
t01267  | 
t01367  | 
t012345  | 
t012346  | 
t012356  | 
t012456  | 
t013456  | 
t023456  | 
t123456  | 
t012347  | 
t012357  | 
t012457  | 
t013457  | 
t023457  | 
t012367  | 
t012467  | 
t013467  | 
t012567  | 
t0123456  | 
t0123457  | 
t0123467  | 
t0123567  | 
t01234567  | 
Notes
    
- Klitizing, (x3x3o3o3o3o3o3o - tene)
 - Klitizing, (o3x3x3o3o3o3o3o - batene)
 - Klitizing, (o3o3x3x3o3o3o3o - tatene)
 - Klitizing, (o3o3o3x3x3o3o3o - be)
 
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 
- (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. "8D uniform polytopes (polyzetta)". x3x3o3o3o3o3o3o - tene, o3x3x3o3o3o3o3o - batene, o3o3x3x3o3o3o3o - tatene, o3o3o3x3x3o3o3o - be
 

















































