7-cubic honeycomb

7-cubic honeycomb
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Type	Regular 7-space honeycomb
Family	Hypercube honeycomb
Schläfli symbol	{4,35,4} {4,34,31,1} {∞}7
Coxeter-Dynkin diagrams
7-face type	{4,3,3,3,3,3}
6-face type	{4,3,3,3,3}
5-face type	{4,3,3,3}
4-face type	{4,3,3}
Cell type	{4,3}
Face type	{4}
Face figure	{4,3} (octahedron)
Edge figure	8 {4,3,3} (16-cell)
Vertex figure	128 {4,35} (7-orthoplex)
Coxeter group	[4,35,4]
Dual	self-dual
Properties	vertex-transitive, edge-transitive, face-transitive, cell-transitive

The 7-cubic honeycomb or hepteractic honeycomb is the only regular space-filling tessellation (or honeycomb) in Euclidean 7-space.

It is analogous to the square tiling of the plane and to the cubic honeycomb of 3-space.

There are many different Wythoff constructions of this honeycomb. The most symmetric form is regular, with Schläfli symbol {4,3⁵,4}. Another form has two alternating 7-cube facets (like a checkerboard) with Schläfli symbol {4,3⁴,3^1,1}. The lowest symmetry Wythoff construction has 128 types of facets around each vertex and a prismatic product Schläfli symbol {∞}⁷.

Related honeycombs

The [4,3⁵,4], , Coxeter group generates 255 permutations of uniform tessellations, 135 with unique symmetry and 134 with unique geometry. The expanded 7-cubic honeycomb is geometrically identical to the 7-cubic honeycomb.

The 7-cubic honeycomb can be alternated into the 7-demicubic honeycomb, replacing the 7-cubes with 7-demicubes, and the alternated gaps are filled by 7-orthoplex facets.

Quadritruncated 7-cubic honeycomb

A quadritruncated 7-cubic honeycomb, , containins all tritruncated 7-orthoplex facets and is the Voronoi tessellation of the D₇^* lattice. Facets can be identically colored from a doubled ${\tilde{C}}_7$×2, [[4,3⁵,4]] symmetry, alternately colored from ${\tilde{C}}_7$, [4,3⁵,4] symmetry, three colors from ${\tilde{B}}_7$, [4,3⁴,3^1,1] symmetry, and 4 colors from ${\tilde{D}}_7$, [3^1,1,3³,3^1,1] symmetry.

See also

• List of regular polytopes

References

• Coxeter, H.S.M. Regular Polytopes, (3rd edition, 1973), Dover edition, ISBN 0-486-61480-8 p. 296, Table II: Regular honeycombs
• 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 24) H.S.M. Coxeter, Regular and Semi-Regular Polytopes III, [Math. Zeit. 200 (1988) 3-45]