Cantellated 24-cells

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24-cell t0 F4.svg
24-cell
CDel node 1.pngCDel 3.pngCDel node.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png
24-cell t02 F4.svg
Cantellated 24-cell
CDel node 1.pngCDel 3.pngCDel node.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png
24-cell t012 F4.svg
Cantitruncated 24-cell
CDel node 1.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png
Orthogonal projections in F4 Coxeter plane

In four-dimensional geometry, a cantellated 24-cell is a convex uniform polychoron, being a cantellation (a 2nd order truncation) of the regular 24-cell.

There are 2 unique degrees of cantellations of the 24-cell including permutations with truncations.


Cantellated 24-cell[edit]

Cantellated 24-cell
Type Uniform polychoron
Schläfli symbol rr{3,4,3}
s2{3,4,3}
Coxeter diagram CDel node 1.pngCDel 3.pngCDel node.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png
CDel node h.pngCDel 3.pngCDel node h.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png
Cells 144 24 Small rhombicuboctahedron.png(3.4.4.4)
24 Cuboctahedron.png(3.4.3.4)

96 Triangular prism.png(3.4.4)

Faces 720 288 triangles
432 squares
Edges 864
Vertices 288
Vertex figure Cantellated 24-cell verf.png
Irreg. triangular prism
Symmetry group F4, [3,4,3]
Properties convex
Uniform index 24 25 26

The cantellated 24-cell or small rhombated icositetrachoron is a uniform polychoron.

The boundary of the cantellated 24-cell is composed of 24 truncated octahedral cells, 24 cuboctahedral cells and 96 triangular prisms. Together they have 288 triangular faces, 432 square faces, 864 edges, and 288 vertices.

Construction[edit]

When the cantellation process is applied to 24-cell, each of the 24 octahedra becomes a small rhombicuboctahedron. In addition however, since each octahedra's edge was previously shared with two other octahedra, the separating edges form the three parallel edges of a triangular prism - 96 triangular prisms, since the 24-cell contains 96 edges. Further, since each vertex was previously shared with 12 faces, the vertex would split into 12 (24*12=288) new vertices. Each group of 12 new vertices forms a cuboctahedron.

Coordinates[edit]

The Cartesian coordinates of the vertices of the cantellated 24-cell having edge length 2 are all permutations of coordinates and sign of:

(0, √2, √2, 2+2√2)
(1, 1+√2, 1+√2, 1+2√2)

The permutations of the second set of coordinates coincide with the vertices of an inscribed runcitruncated tesseract.

The dual configuration has all permutations and signs of:

(0,2,2+√2,2+√2)
(1,1,1+√2,3+√2)

Structure[edit]

The 24 small rhombicuboctahedra are joined to each other via their triangular faces, to the cuboctahedra via their axial square faces, and to the triangular prisms via their off-axial square faces. The cuboctahedra are joined to the triangular prisms via their triangular faces. Each triangular prism is joined to two cuboctahedra at its two ends.

Cantic snub 24-cell[edit]

A half-symmetry construction of the cantellated 24-cell, also called a cantic snub 24-cell, as CDel node h.pngCDel 3.pngCDel node h.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png, has an identical geometry, but its triangular faces are further subdivided. The cantellated 24-cell has 2 positions of triangular faces in ratio of 96 and 192, while the cantic snub 24-cell has 3 positions of 96 triangles.

The difference can be seen in the vertex figures, with edges representing faces in the polychoron:

Cantellated 24-cell verf.png
CDel node 1.pngCDel 3.pngCDel node.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png
Cantic snub 24-cell verf.png
CDel node h.pngCDel 3.pngCDel node h.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png

Images[edit]

orthographic projections
Coxeter plane F4
Graph 24-cell t02 F4.svg
Dihedral symmetry [12]
Coxeter plane B3 / A2 (a) B3 / A2 (b)
Graph 24-cell t02 B3.svg 24-cell t13 B3.svg
Dihedral symmetry [6] [6]
Coxeter plane B4 B2 / A2
Graph 24-cell t02 B4.svg 24-cell t02 B2.svg
Dihedral symmetry [8] [4]
Schlegel diagrams
Cantel 24cell1.png
Schlegel diagram
Cantel 24cell2.png
Showing 24 cuboctahedra.
Cantel 24cell3.png
Showing 96 triangular prisms.

Cantitruncated 24-cell[edit]

Cantitruncated 24-cell
Cantitruncated 24-cell schlegel halfsolid.png
Schlegel diagram, centered on truncated cuboctahedron
Type Uniform polychoron
Schläfli symbol tr{3,4,3}
Coxeter diagram CDel node 1.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png
Cells 144 24 4.6.8 Great rhombicuboctahedron.png
96 4.4.3 Triangular prism.png
24 3.8.8 Truncated hexahedron.png
Faces 720 192{3}
288{4}
96{6}
144{8}
Edges 1152
Vertices 576
Vertex figure Cantitruncated 24-cell verf.png
sphenoid
Symmetry group F4, [3,4,3]
Properties convex
Uniform index 27 28 29

The cantitruncated 24-cell or great rhombated icositetrachoron is a uniform polychoron derived from the 24-cell. It is bounded by 24 truncated cuboctahedra corresponding with the cells of a 24-cell, 24 truncated cubes corresponding with the cells of the dual 24-cell, and 96 triangular prisms corresponding with the edges of the first 24-cell.

Coordinates[edit]

The Cartesian coordinates of a cantitruncated 24-cell having edge length 2 are all permutations of coordinates and sign of:

(1,1+√2,1+2√2,3+3√2)
(0,2+√2,2+2√2,2+3√2)

The dual configuration has coordinates as all permutations and signs of:

(1,1+√2,1+√2,5+2√2)
(1,3+√2,3+√2,3+2√2)
(2,2+√2,2+√2,4+2√2)

Projections[edit]

orthographic projections
Coxeter plane F4
Graph 24-cell t123 F4.svg
Dihedral symmetry [12]
Coxeter plane B3 / A2 (a) B3 / A2 (b)
Graph 24-cell t123 B3.svg 24-cell t0123 B3.svg
Dihedral symmetry [6] [6]
Coxeter plane B4 B2 / A2
Graph 24-cell t123 B4.svg 24-cell t123 B2.svg
Dihedral symmetry [8] [4]
Stereographic projection
Cantitruncated 24 cell.png

Related polytopes[edit]

Name 24-cell truncated 24-cell snub 24-cell rectified 24-cell cantellated 24-cell bitruncated 24-cell cantitruncated 24-cell runcinated 24-cell runcitruncated 24-cell omnitruncated 24-cell
Schläfli
symbol
{3,4,3} t0,1{3,4,3}
t{3,4,3}
s{3,4,3} t1{3,4,3}
r{3,4,3}
t0,2{3,4,3}
rr{3,4,3}
t1,2{3,4,3}
2t{3,4,3}
t0,1,2{3,4,3}
tr{3,4,3}
t0,3{3,4,3} t0,1,3{3,4,3} t0,1,2,3{3,4,3}
Coxeter
diagram
CDel node 1.pngCDel 3.pngCDel node.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png CDel node h.pngCDel 3.pngCDel node h.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png CDel node.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 3.pngCDel node.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png CDel node.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 3.pngCDel node.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node 1.png CDel node 1.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node 1.png CDel node 1.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node 1.png
Schlegel
diagram
Schlegel wireframe 24-cell.png Schlegel half-solid truncated 24-cell.png Schlegel half-solid alternated cantitruncated 16-cell.png Schlegel half-solid cantellated 16-cell.png Cantel 24cell1.png Bitruncated 24-cell Schlegel halfsolid.png Cantitruncated 24-cell schlegel halfsolid.png Runcinated 24-cell Schlegel halfsolid.png Runcitruncated 24-cell.png Omnitruncated 24-cell.png
F4 24-cell t0 F4.svg 24-cell t01 F4.svg 24-cell h01 F4.svg 24-cell t1 F4.svg 24-cell t02 F4.svg 24-cell t12 F4.svg 24-cell t012 F4.svg 24-cell t03 F4.svg 24-cell t013 F4.svg 24-cell t0123 F4.svg
B4 24-cell t0 B4.svg 4-cube t123.svg 24-cell h01 B4.svg 24-cell t1 B4.svg 24-cell t02 B4.svg 24-cell t12 B4.svg 24-cell t012 B4.svg 24-cell t03 B4.svg 24-cell t013 B4.svg 24-cell t0123 B4.svg
B3(a) 4-cube t0 B3.svg 24-cell t01 B3.svg 24-cell h01 B3.svg 24-cell t1 B3.svg 24-cell t02 B3.svg 24-cell t12 B3.svg 24-cell t012 B3.svg 24-cell t03 B3.svg 24-cell t013 B3.svg 24-cell t0123 B3.svg
B3(b) 24-cell t3 B3.svg 24-cell t23 B3.svg 24-cell t2 B3.svg 24-cell t13 B3.svg 24-cell t123 B3.svg 24-cell t023 B3.svg
B2 24-cell t0 B2.svg 24-cell t01 B2.svg 24-cell h01 B2.svg 24-cell t1 B2.svg 24-cell t02 B2.svg 24-cell t12 B2.svg 24-cell t012 B2.svg 24-cell t03 B2.svg 24-cell t013 B2.svg 24-cell t0123 B2.svg

References[edit]

  • T. Gosset: On the Regular and Semi-Regular Figures in Space of n Dimensions, Messenger of Mathematics, Macmillan, 1900
  • H.S.M. Coxeter:
    • Coxeter, Regular Polytopes, (3rd edition, 1973), Dover edition, ISBN 0-486-61480-8, p.296, Table I (iii): Regular Polytopes, three regular polytopes in n-dimensions (n≥5)
    • H.S.M. Coxeter, Regular Polytopes, 3rd Edition, Dover New York, 1973, p.296, Table I (iii): Regular Polytopes, three regular polytopes in n-dimensions (n≥5)
    • 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]
  • John H. Conway, Heidi Burgiel, Chaim Goodman-Strass, The Symmetries of Things 2008, ISBN 978-1-56881-220-5 (Chapter 26. pp. 409: Hemicubes: 1n1)
  • Norman Johnson Uniform Polytopes, Manuscript (1991)
    • N.W. Johnson: The Theory of Uniform Polytopes and Honeycombs, Ph.D. (1966)
  • 3. Convex uniform polychora based on the icositetrachoron (24-cell) - Model 24, 25, George Olshevsky.
  • Richard Klitzing, 4D, uniform polytopes (polychora) x3o4x3o - srico, o3x4x3o - grico