- Octacross
An octacross, is a regular
8-polytope with 16 vertices, 112 edges, 448 triangle faces, 1120 octahedron cells, 17925-cell s "4-faces", 1792 "5-faces", 1024 "6-faces", and 256 "7-faces".It is a part of an infinite family of polytopes, called
cross-polytope s or "orthoplexes". The dual polytope is an 8-hypercube , orocteract .The name "octacross" is derived from combining the family name "cross polytope" with "oct" for eight (dimensions) in Greek.
Construction
There are two
Coxeter group s associated with the "octacross", one regular, dual of theocteract with the C8 or [4,3,3,3,3,3,3] symmetry group, and a lower symmetry with two copies of 7-simplex facets, alternating, with the D8 or [35,1,1] symmetry group.Cartesian coordinates
Cartesian coordinates for the vertices of an octacross, centered at the origin are: (±1,0,0,0,0,0,0,0), (0,±1,0,0,0,0,0,0), (0,0,±1,0,0,0,0,0), (0,0,0,±1,0,0,0,0), (0,0,0,0,±1,0,0,0), (0,0,0,0,0,±1,0,0), (0,0,0,0,0,0,0,±1), (0,0,0,0,0,0,0,±1)Every vertex pair is connected by an edge, except opposites.
See also
* Other
8-polytope s:
**8-simplex - {37}
**8-cube (octeract) - {4,36}
**8-demicube (demiocteract) - {31,5,1}
** 421 polytope - {34,2,1}
** 241 polytope - {32,4,1}
** 142 polytope - {31,4,2}
* Others in thecross-polytope family
**Octahedron - {3,4}
**Hexadecachoron - {3,3,4}
**Pentacross - {33,4}
**Hexacross - {34,4}
**Heptacross - {35,4}
**Octacross - {36,4}
**Enneacross - {37,4}
**Decacross - {38,4}External links
*GlossaryForHyperspace | anchor=Cross | title=Cross polytope
* [http://members.cox.net/hedrondude/topes.htm Polytopes of Various Dimensions]
* [http://tetraspace.alkaline.org/glossary.htm Multi-dimensional Glossary]
Wikimedia Foundation. 2010.