Rectified 5-cell | ||
![]() Schlegel diagram with the 5 tetrahedral cells shown. | ||
Type | Uniform 4-polytope | |
Schläfli symbol | t1{3,3,3} or r{3,3,3} {32,1} = | |
Coxeter-Dynkin diagram | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | |
Cells | 10 | 5 {3,3} ![]() 5 3.3.3.3 ![]() |
Faces | 30 {3} | |
Edges | 30 | |
Vertices | 10 | |
Vertex figure | ![]() Triangular prism | |
Symmetry group | A4, [3,3,3], order 120 | |
Petrie polygon | Pentagon | |
Properties | convex, isogonal, isotoxal | |
Uniform index | 1 2 3 |
In four-dimensional geometry, the rectified 5-cell is a uniform 4-polytope composed of 5 regular tetrahedral and 5 regular octahedral cells. Each edge has one tetrahedron and two octahedra. Each vertex has two tetrahedra and three octahedra. In total it has 30 triangle faces, 30 edges, and 10 vertices. Each vertex is surrounded by 3 octahedra and 2 tetrahedra; the vertex figure is a triangular prism.
Topologically, under its highest symmetry, [3,3,3], there is only one geometrical form, containing 5 regular tetrahedra and 5 rectified tetrahedra (which is geometrically the same as a regular octahedron). It is also topologically identical to a tetrahedron-octahedron segmentochoron.[ clarification needed ]
The vertex figure of the rectified 5-cell is a uniform triangular prism, formed by three octahedra around the sides, and two tetrahedra on the opposite ends. [1]
Despite having the same number of vertices as cells (10) and the same number of edges as faces (30), the rectified 5-cell is not self-dual because the vertex figure (a uniform triangular prism) is not a dual of the polychoron's cells.
Seen in a configuration matrix, all incidence counts between elements are shown. The diagonal f-vector numbers are derived through the Wythoff construction, dividing the full group order of a subgroup order by removing one mirror at a time. [2]
A4 | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | k-face | fk | f0 | f1 | f2 | f3 | k-figure | Notes | ||
---|---|---|---|---|---|---|---|---|---|---|---|
A2A1 | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ( ) | f0 | 10 | 6 | 3 | 6 | 3 | 2 | {3}x{ } | A4/A2A1 = 5!/3!/2 = 10 |
A1A1 | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | { } | f1 | 2 | 30 | 1 | 2 | 2 | 1 | { }v( ) | A4/A1A1 = 5!/2/2 = 30 |
A2A1 | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | {3} | f2 | 3 | 3 | 10 | * | 2 | 0 | { } | A4/A2A1 = 5!/3!/2 = 10 |
A2 | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | 3 | 3 | * | 20 | 1 | 1 | A4/A2 = 5!/3! = 20 | |||
A3 | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | r{3,3} | f3 | 6 | 12 | 4 | 4 | 5 | * | ( ) | A4/A3 = 5!/4! = 5 |
A3 | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | {3,3} | 4 | 6 | 0 | 4 | * | 5 |
Together with the simplex and 24-cell, this shape and its dual (a polytope with ten vertices and ten triangular bipyramid facets) was one of the first 2-simple 2-simplicial 4-polytopes known. This means that all of its two-dimensional faces, and all of the two-dimensional faces of its dual, are triangles. In 1997, Tom Braden found another dual pair of examples, by gluing two rectified 5-cells together; since then, infinitely many 2-simple 2-simplicial polytopes have been constructed. [3] [4]
It is one of three semiregular 4-polytopes made of two or more cells which are Platonic solids, discovered by Thorold Gosset in his 1900 paper. He called it a tetroctahedric for being made of tetrahedron and octahedron cells. [5]
E. L. Elte identified it in 1912 as a semiregular polytope, labeling it as tC5.
Ak Coxeter plane | A4 | A3 | A2 |
---|---|---|---|
Graph | ![]() | ![]() | ![]() |
Dihedral symmetry | [5] | [4] | [3] |
![]() stereographic projection (centered on octahedron) | ![]() Net (polytope) |
![]() | Tetrahedron-centered perspective projection into 3D space, with nearest tetrahedron to the 4D viewpoint rendered in red, and the 4 surrounding octahedra in green. Cells lying on the far side of the polytope have been culled for clarity (although they can be discerned from the edge outlines). The rotation is only of the 3D projection image, in order to show its structure, not a rotation in 4D space. |
The Cartesian coordinates of the vertices of an origin-centered rectified 5-cell having edge length 2 are:
Coordinates | |
---|---|
More simply, the vertices of the rectified 5-cell can be positioned on a hyperplane in 5-space as permutations of (0,0,0,1,1) or (0,0,1,1,1). These construction can be seen as positive orthant facets of the rectified pentacross or birectified penteract respectively.
The rectified 5-cell is the vertex figure of the 5-demicube, and the edge figure of the uniform 221 polytope.
The convex hull the rectified 5-cell and its dual (of the same long radius) is a nonuniform polychoron composed of 30 cells: 10 tetrahedra, 20 octahedra (as triangular antiprisms), and 20 vertices. Its vertex figure is a triangular bifrustum.
The rectified 5-cell is one of 9 Uniform 4-polytopes constructed from the [3,3,3] Coxeter group.
Name | 5-cell | truncated 5-cell | rectified 5-cell | cantellated 5-cell | bitruncated 5-cell | cantitruncated 5-cell | runcinated 5-cell | runcitruncated 5-cell | omnitruncated 5-cell |
---|---|---|---|---|---|---|---|---|---|
Schläfli symbol | {3,3,3} 3r{3,3,3} | t{3,3,3} 2t{3,3,3} | r{3,3,3} 2r{3,3,3} | rr{3,3,3} r2r{3,3,3} | 2t{3,3,3} | tr{3,3,3} t2r{3,3,3} | t0,3{3,3,3} | t0,1,3{3,3,3} t0,2,3{3,3,3} | t0,1,2,3{3,3,3} |
Coxeter diagram | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
Schlegel diagram | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
A4 Coxeter plane Graph | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
A3 Coxeter plane Graph | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
A2 Coxeter plane Graph | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
The rectified 5-cell is second in a dimensional series of semiregular polytopes. Each progressive uniform polytope is constructed as the vertex figure of the previous polytope. Thorold Gosset identified this series in 1900 as containing all regular polytope facets, containing all simplexes and orthoplexes (tetrahedrons and octahedrons in the case of the rectified 5-cell). The Coxeter symbol for the rectified 5-cell is 021.
k21 figures in n dimensional | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Space | Finite | Euclidean | Hyperbolic | ||||||||
En | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |||
Coxeter group | E3=A2A1 | E4=A4 | E5=D5 | E6 | E7 | E8 | E9 = = E8+ | E10 = = E8++ | |||
Coxeter diagram | ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | |||
Symmetry | [3−1,2,1] | [30,2,1] | [31,2,1] | [32,2,1] | [33,2,1] | [34,2,1] | [35,2,1] | [36,2,1] | |||
Order | 12 | 120 | 1,920 | 51,840 | 2,903,040 | 696,729,600 | ∞ | ||||
Graph | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | - | - | |||
Name | −121 | 021 | 121 | 221 | 321 | 421 | 521 | 621 |
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 | ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
In geometry, a convex uniform honeycomb is a uniform tessellation which fills three-dimensional Euclidean space with non-overlapping convex uniform polyhedral cells.
A cuboctahedron is a polyhedron with 8 triangular faces and 6 square faces. A cuboctahedron has 12 identical vertices, with 2 triangles and 2 squares meeting at each, and 24 identical edges, each separating a triangle from a square. As such, it is a quasiregular polyhedron, i.e. an Archimedean solid that is not only vertex-transitive but also edge-transitive. It is radially equilateral.
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In geometry, the snub 24-cell or snub disicositetrachoron is a convex uniform 4-polytope composed of 120 regular tetrahedral and 24 icosahedral cells. Five tetrahedra and three icosahedra meet at each vertex. In total it has 480 triangular faces, 432 edges, and 96 vertices. One can build it from the 600-cell by diminishing a select subset of icosahedral pyramids and leaving only their icosahedral bases, thereby removing 480 tetrahedra and replacing them with 24 icosahedra.
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