16-cell
| 16-cell (4-orthoplex) | |
|---|---|
| Schlegel diagram (vertices and edges) | |
| Type | Convex regular 4-polytope 4-orthoplex 4-demicube | 
| Schläfli symbol | {3,3,4} | 
| Coxeter diagram | |
| Cells | 16 {3,3} | 
| Faces | 32 {3} | 
| Edges | 24 | 
| Vertices | 8 | 
| Vertex figure | Octahedron | 
| Petrie polygon | octagon | 
| Coxeter group | B4, [3,3,4], order 384 D4, order 192 | 
| Dual | Tesseract | 
| Properties | convex, isogonal, isotoxal, isohedral, regular, Hanner polytope | 
| Uniform index | 12 | 
In geometry, the 16-cell is the regular convex 4-polytope (four-dimensional analogue of a Platonic solid) with Schläfli symbol {3,3,4}. It is one of the six regular convex 4-polytopes first described by the Swiss mathematician Ludwig Schläfli in the mid-19th century. It is also called C16, hexadecachoron, or hexdecahedroid [sic?].
It is the 4-dimensional member of an infinite family of polytopes called cross-polytopes, orthoplexes, or hyperoctahedrons which are analogous to the octahedron in three dimensions. It is Coxeter's polytope. The dual polytope is the tesseract (4-cube), which it can be combined with to form a compound figure. The cells of the 16-cell are dual to the 16 vertices of the tesseract.