16-cell honeycomb

16-cell honeycomb

Perspective projection: the first layer of adjacent 16-cell facets.
Type Regular 4-space honeycomb
Family Alternated hypercube honeycomb
Schläfli symbol {3,3,4,3}
Coxeter-Dynkin diagram
4-face type {3,3,4}
Cell type {3,3}
Face type {3}
Edge figure cube
Vertex figure 24-cell (Rectified 16-cell)
Coxeter group {\tilde{F}}_4
Dual {3,4,3,3}
Properties vertex-transitive, edge-transitive, face-transitive, cell-transitive

In four-dimensional Euclidean geometry, the 16-cell honeycomb is the one of three regular space-filling tessellation (or honeycomb) in Euclidean 4-space. The other two are the tesseractic honeycomb and the 24-cell honeycomb. This honeycomb is constructed from 16-cell facets, three around every edge. It has a 24-cell vertex figure.

This vertex arrangement or lattice is called the B4, D4, or F4 lattice.[1][2]

Contents

Alternate names

Coordinates

As a regular honeycomb, {3,3,4,3}, it has no lower dimensional analogues, but as an alternated form (the demitesseractic honeycomb, h{4,3,3,4}) it is related to the alternated cubic honeycomb.

Vertices can be placed at all integer coordinates (i,j,k,l), such that the sum of the coordinates is even.

Kissing number

The vertices of this tessellation are the centers of the 3-spheres in the densest possible packing of equal spheres in 4-space; its kissing number is 24, which is also the highest possible in 4-space.[3]

Symmetry constructions

There are three different symmetry constructions of this tessellation. Each symmetry can be represented by different arrangements of colored 16-cell facets.

Name Coxeter group Schläfli symbol Coxeter-Dynkin diagram Vertex figure Facets/verf
16-cell honeycomb {\tilde{F}}_4 = [3,3,4,3] {3,3,4,3} 24: 16-cell
4-demicube honeycomb {\tilde{B}}_4 = [31,1,3,4] {31,1,3,4} = h{4,3,3,4} = 16+8: 16-cell
{\tilde{D}}_4 = [31,1,1,1] {31,1,1,1} = h{4,3,31,1} = 8+8+8: 16-cell

See also

Notes

  1. ^ http://www2.research.att.com/~njas/lattices/F4.html
  2. ^ http://www2.research.att.com/~njas/lattices/D4.html
  3. ^ O. R. Musin (2003). "The problem of the twenty-five spheres". Russ. Math. Surv. 58: 794–795. doi:10.1070/RM2003v058n04ABEH000651. 

References