Rectified 6-orthoplexes#Rectified 6-orthoplex

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6-orthoplex
{{CDD|node_1|3|node|3|node|3|node|3|node|4|node}}

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Rectified 6-orthoplex
{{CDD|node|3|node_1|3|node|3|node|3|node|4|node}}

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Birectified 6-orthoplex
{{CDD|node|3|node|3|node_1|3|node|3|node|4|node}}

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Birectified 6-cube
{{CDD|node|3|node|3|node|3|node_1|3|node|4|node}}

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Rectified 6-cube
{{CDD|node|3|node|3|node|3|node|3|node_1|4|node}}

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6-cube
{{CDD|node|3|node|3|node|3|node|3|node|4|node_1}}

colspan=4|Orthogonal projections in B6 Coxeter plane

In six-dimensional geometry, a rectified 6-orthoplex is a convex uniform 6-polytope, being a rectification of the regular 6-orthoplex.

There are unique 6 degrees of rectifications, the zeroth being the 6-orthoplex, and the 6th and last being the 6-cube. Vertices of the rectified 6-orthoplex are located at the edge-centers of the 6-orthoplex. Vertices of the birectified 6-orthoplex are located in the triangular face centers of the 6-orthoplex.

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Rectified 6-orthoplex

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!bgcolor=#e7dcc3 colspan=2|Rectified hexacross

bgcolor=#e7dcc3|Typeuniform 6-polytope
bgcolor=#e7dcc3|Schläfli symbolst1{34,4} or r{34,4}
\left\{\begin{array}{l}3, 3, 3, 4\\3\end{array}\right\}
r{3,3,3,31,1}
bgcolor=#e7dcc3|Coxeter-Dynkin diagrams{{CDD|node|3|node_1|3|node|3|node|3|node|4|node}} = {{CDD|node_1|split1|nodes|3a|nodea|3a|nodea|4a|nodea}}
{{CDD|node|3|node_1|3|node|3|node|split1|nodes}} = {{CDD|nodes|3ab|nodes_10lr|split5c|nodes}}
bgcolor=#e7dcc3|5-faces76 total:
64 rectified 5-simplex
12 5-orthoplex
bgcolor=#e7dcc3|4-faces576 total:
192 rectified 5-cell
384 5-cell
bgcolor=#e7dcc3|Cells1200 total:
240 octahedron
960 tetrahedron
bgcolor=#e7dcc3|Faces1120 total:
160 and 960 triangles
bgcolor=#e7dcc3|Edges480
bgcolor=#e7dcc3|Vertices60
bgcolor=#e7dcc3|Vertex figure16-cell prism
bgcolor=#e7dcc3|Petrie polygonDodecagon
bgcolor=#e7dcc3|Coxeter groupsB6, [3,3,3,3,4]
D6, [33,1,1]
bgcolor=#e7dcc3|Propertiesconvex

The rectified 6-orthoplex is the vertex figure for the demihexeractic honeycomb.

:{{CDD|nodes_10ru|split2|node|3|node|3|node|split1|nodes}} or {{CDD|nodes_10ru|split2|node|3|node|3|node|3|node|4|node}}

= Alternate names =

  • rectified hexacross
  • rectified hexacontitetrapeton (acronym: rag) (Jonathan Bowers){{sfn|Klitzing|at=[https://bendwavy.org/klitzing/incmats/rag.htm (o3x3o3o3o4o - rag)]}}

= Construction =

There are two Coxeter groups associated with the rectified hexacross, one with the C6 or [4,3,3,3,3] Coxeter group, and a lower symmetry with two copies of pentacross facets, alternating, with the D6 or [33,1,1] Coxeter group.

= Cartesian coordinates =

Cartesian coordinates for the vertices of a rectified hexacross, centered at the origin, edge length \sqrt{2}\ are all permutations of:

: (±1,±1,0,0,0,0)

= Images =

{{6-cube Coxeter plane graphs|t4|150}}

= Root vectors =

The 60 vertices represent the root vectors of the simple Lie group D6. The vertices can be seen in 3 hyperplanes, with the 15 vertices rectified 5-simplices cells on opposite sides, and 30 vertices of an expanded 5-simplex passing through the center. When combined with the 12 vertices of the 6-orthoplex, these vertices represent the 72 root vectors of the B6 and C6 simple Lie groups.

The 60 roots of D6 can be geometrically folded into H3 (Icosahedral symmetry), as {{CDD|nodes|3ab|nodes_10lr|split5c|nodes}} to {{CDD|node|3|node_1|5|node}}, creating 2 copies of 30-vertex icosidodecahedra, with the Golden ratio between their radii:[https://blogs.ams.org/visualinsight/2015/01/01/icosidodecahedron-from-projected-d6-root-polytope Icosidodecahedron from D6] John Baez, January 1, 2015

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colspan=2|Rectified 6-orthoplex

!2 icosidodecahedra

3D (H3 projection)

!A4/B5/D6 Coxeter plane

!H2 Coxeter plane

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Birectified 6-orthoplex

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!bgcolor=#e7dcc3 colspan=2|Birectified 6-orthoplex

bgcolor=#e7dcc3|Typeuniform 6-polytope
bgcolor=#e7dcc3|Schläfli symbolst2{34,4} or 2r{34,4}
\left\{\begin{array}{l}3, 3, 4\\3, 3\end{array}\right\}
t2{3,3,3,31,1}
bgcolor=#e7dcc3|Coxeter-Dynkin diagrams{{CDD|node|3|node|3|node_1|3|node|3|node|4|node}} = {{CDD|node_1|split1|nodes|3ab|nodes|4a|nodea}}
{{CDD|node|3|node|3|node_1|3|node|split1|nodes}} = {{CDD|nodes|3ab|nodes|split5c|nodes_01l}}
bgcolor=#e7dcc3|5-faces76
bgcolor=#e7dcc3|4-faces636
bgcolor=#e7dcc3|Cells2160
bgcolor=#e7dcc3|Faces2880
bgcolor=#e7dcc3|Edges1440
bgcolor=#e7dcc3|Vertices160
bgcolor=#e7dcc3|Vertex figure{3}×{3,4} duoprism
bgcolor=#e7dcc3|Petrie polygonDodecagon
bgcolor=#e7dcc3|Coxeter groupsB6, [3,3,3,3,4]
D6, [33,1,1]
bgcolor=#e7dcc3|Propertiesconvex

The birectified 6-orthoplex can tessellation space in the trirectified 6-cubic honeycomb.

= Alternate names =

  • birectified hexacross
  • birectified hexacontitetrapeton (acronym: brag) (Jonathan Bowers){{sfn|Klitzing|at=[https://bendwavy.org/klitzing/incmats/brag.htm (o3o3x3o3o4o - brag)]}}

= Cartesian coordinates =

Cartesian coordinates for the vertices of a rectified hexacross, centered at the origin, edge length \sqrt{2}\ are all permutations of:

: (±1,±1,±1,0,0,0)

= Images =

{{6-cube Coxeter plane graphs|t3|150}}

It can also be projected into 3D-dimensions as {{CDD|nodes|3ab|nodes|split5c|nodes_01l}} → {{CDD|node|3|node|5|node_1}}, a dodecahedron envelope.

Related polytopes

These polytopes are a part a family of 63 Uniform 6-polytopes generated from the B6 Coxeter plane, including the regular 6-cube or 6-orthoplex.

{{Hexeract family}}

Notes

{{reflist}}

References

  • H.S.M. Coxeter:
  • H.S.M. Coxeter, Regular Polytopes, 3rd Edition, Dover New York, 1973
  • 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, [https://www.wiley.com/en-us/Kaleidoscopes-p-9780471010036 wiley.com], {{isbn|978-0-471-01003-6}}
  • (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]
  • Norman Johnson Uniform Polytopes, Manuscript (1991)
  • N.W. Johnson: The Theory of Uniform Polytopes and Honeycombs, Ph.D.
  • {{KlitzingPolytopes|polypeta.htm|6D uniform polytopes (polypeta) with acronyms}} o3x3o3o3o4o - rag, o3o3x3o3o4o - brag {{sfn whitelist| CITEREFKlitzing}}