Cubic tegum

Cubic tegum
(OFF file)
Rank	4
Type	CRF
Notation
Bowers style acronym	Cute
Coxeter diagram	oxo4ooo3ooo&#xt
Bracket notation	<[III]I>
Elements
Cells	12 square pyramids
Faces	24 triangles, 6 squares
Edges	12+16
Vertices	2+8
Vertex figures	2 cubes, edge length 1
	8 skewed triangular tegums, based edge length √2, side edge length 1
Measures (edge length 1)
Inradius	${\frac {\sqrt {2}}{4}}\approx 0.35355$
Hypervolume	${\frac {1}{4}}=0.25$
Dichoral angles	Squippy–3–squippy: 120°
	Squippy–4–squippy: 90°
Height	1
Central density	1
Related polytopes
Dual	Semi-uniform octahedral prism
Conjugate	None
Convex hull	Cubic tegum
Abstract & topological properties
Euler characteristic	0
Orientable	Yes
Properties
Symmetry	B3×A1, order 96
Convex	Yes
Nature	Tame

The cubic tegum, also called the cubic bipyramid, is a CRF polychoron with 12 square pyramids as cells. As the name suggests, it is a tegum based on the cube, formed by attaching 2 cubic pyramids together at their common base. It is unique among CRF tegums as the height from the top to the bottom vertex is identical to the cube's edge length.

A regular icositetrachoron can be decomposed into 8 CRF cubic tegums sharing one common vertex.

Gallery

• 

  Wireframe, cell, net

Vertex coordinates

Coordinates for the vertices of a cubic tegum of edge length 1 are given by:

• $\left(\pm {\frac {1}{2}},\,\pm {\frac {1}{2}},\,\pm {\frac {1}{2}},\,0\right),$
• $\left(0,\,0,\,0,\,\pm {\frac {1}{2}}\right).$

Representations

A cubic tegum has the following Coxeter diagrams:

• oxo4ooo3ooo&#xt (full symmetry)
• oxo oxo4ooo&#xt (square prismatic tegum)
• oxo oxo oxo&#xt (cuboid tegum)
• xo ox4oo3oo&#zx
• oxo xox4ooo&#xt (square-first)
• oxo xox xox&#xt (as above with rectangular symmetry)

Variations

The cubic tegum can have the heights of its pyramids varied while maintaining its full symmetry. These variants generally have 12 non-CRF square pyramids as cells.

One notable variation can be obtained as the dual of the uniform octahedral prism, which can be represented by m2o4o3m. In this variation the height between the top and bottom vertices of the tegum is ${\sqrt {2}}\approx 1.41421$ times the length of the edges of the base cube, and all the dichoral angles are $\arccos \left(-{\frac {1}{3}}\right)\approx 109.47122^{\circ }$.

External links

• Bowers, Jonathan. "Four Dimensional Dice Up To Twenty Sides".

• Klitzing, Richard. "cute".
• Hi.gher.Space Wiki Contributors. "Cubic bipyramid".