Convex uniform honeycomb

The alternated cubic honeycomb is one of 28 space-filling uniform tessellations in Euclidean 3-space, composed of alternating yellow tetrahedra and red octahedra.

In geometry, a convex uniform honeycomb is a uniform tessellation which fills three-dimensional Euclidean space with non-overlapping convex uniform polyhedral cells.

Twenty-eight such honeycombs are known:

• the familiar cubic honeycomb and 7 truncations thereof;
• the alternated cubic honeycomb and 4 truncations thereof;
• 10 prismatic forms based on the uniform plane tilings (11 if including the cubic honeycomb);
• 5 modifications of some of the above by elongation and/or gyration.

They can be considered the three-dimensional analogue to the uniform tilings of the plane.

The Voronoi diagram of any lattice forms a convex uniform honeycomb in which the cells are zonohedra.

History

• 1900: Thorold Gosset enumerated the list of semiregular convex polytopes with regular cells (Platonic solids) in his publication On the Regular and Semi-Regular Figures in Space of n Dimensions, including one regular cubic honeycomb, and two semiregular forms with tetrahedra and octahedra.
• 1905: Alfredo Andreini enumerated 25 of these tessellations.
• 1991: Norman Johnson's manuscript Uniform Polytopes identified the list of 28.
• 1994: Branko Grünbaum, in his paper Uniform tilings of 3-space, also independently enumerated all 28, after discovering errors in Andreini's publication. He found the 1905 paper, which listed 25, had 1 wrong, and 4 being missing. Grünbaum states in this paper that Norman Johnson deserves priority for achieving the same enumeration in 1991. He also mentions that I. Alexeyev of Russia had contacted him regarding a putative enumeration of these forms, but that Grünbaum was unable to verify this at the time.
• 2006: George Olshevsky, in his manuscript Uniform Panoploid Tetracombs, along with repeating the derived list of 11 convex uniform tilings, and 28 convex uniform honeycombs, expands a further derived list of 143 convex uniform tetracombs (Honeycombs of uniform 4-polytopes in 4-space).

Only 14 of the convex uniform polyhedra appear in these patterns:

• three of the five Platonic solids (the tetrahedron, cube, and octahedron),
• six of the thirteen Archimedean solids (the ones with reflective tetrahedral or octahedral symmetry), and
• five of the infinite family of prisms (the 3-, 4-, 6-, 8-, and 12-gonal ones; the 4-gonal prism duplicates the cube).

The icosahedron, snub cube, and square antiprism appear in some alternations, but those honeycombs cannot be realised with all edges unit length.

Names

This set can be called the regular and semiregular honeycombs. It has been called the Archimedean honeycombs by analogy with the convex uniform (non-regular) polyhedra, commonly called Archimedean solids. Recently Conway has suggested naming the set as the Architectonic tessellations and the dual honeycombs as the Catoptric tessellations.

The individual honeycombs are listed with names given to them by Norman Johnson. (Some of the terms used below are defined in Uniform 4-polytope#Geometric derivations for 46 nonprismatic Wythoffian uniform 4-polytopes)

For cross-referencing, they are given with list indices from Andreini (1-22), Williams(1–2,9-19), Johnson (11–19, 21–25, 31–34, 41–49, 51–52, 61–65), and Grünbaum(1-28). Coxeter uses δ₄ for a cubic honeycomb, hδ₄ for an alternated cubic honeycomb, qδ₄ for a quarter cubic honeycomb, with subscripts for other forms based on the ring patterns of the Coxeter diagram.

Compact Euclidean uniform tessellations (by their infinite Coxeter group families)

Fundamental domains in a cubic element of three groups.

Family correspondences

The fundamental infinite Coxeter groups for 3-space are:

1. The ${\tilde {C}}_{3}$, [4,3,4], cubic, (8 unique forms plus one alternation)
2. The ${\tilde {B}}_{3}$, [4,3^1,1], alternated cubic, (11 forms, 3 new)
3. The ${\tilde {A}}_{3}$ cyclic group, [(3,3,3,3)] or [3^[4]], (5 forms, one new)

There is a correspondence between all three families. Removing one mirror from ${\tilde {C}}_{3}$ produces ${\tilde {B}}_{3}$, and removing one mirror from ${\tilde {B}}_{3}$ produces ${\tilde {A}}_{3}$. This allows multiple constructions of the same honeycombs. If cells are colored based on unique positions within each Wythoff construction, these different symmetries can be shown.

In addition there are 5 special honeycombs which don't have pure reflectional symmetry and are constructed from reflectional forms with elongation and gyration operations.

The total unique honeycombs above are 18.

The prismatic stacks from infinite Coxeter groups for 3-space are:

1. The ${\tilde {C}}_{2}$×${\tilde {I}}_{1}$, [4,4,2,∞] prismatic group, (2 new forms)
2. The ${\tilde {G}}_{2}$×${\tilde {I}}_{1}$, [6,3,2,∞] prismatic group, (7 unique forms)
3. The ${\tilde {A}}_{2}$×${\tilde {I}}_{1}$, [(3,3,3),2,∞] prismatic group, (No new forms)
4. The ${\tilde {I}}_{1}$×${\tilde {I}}_{1}$×${\tilde {I}}_{1}$, [∞,2,∞,2,∞] prismatic group, (These all become a cubic honeycomb)

In addition there is one special elongated form of the triangular prismatic honeycomb.

The total unique prismatic honeycombs above (excluding the cubic counted previously) are 10.

Combining these counts, 18 and 10 gives us the total 28 uniform honeycombs.

The C̃₃, [4,3,4] group (cubic)

The regular cubic honeycomb, represented by Schläfli symbol {4,3,4}, offers seven unique derived uniform honeycombs via truncation operations. (One redundant form, the runcinated cubic honeycomb, is included for completeness though identical to the cubic honeycomb.) The reflectional symmetry is the affine Coxeter group [4,3,4]. There are four index 2 subgroups that generate alternations: [1⁺,4,3,4], [(4,3,4,2⁺)], [4,3⁺,4], and [4,3,4]⁺, with the first two generated repeated forms, and the last two are nonuniform.

C3 honeycombs
Space group	Fibrifold	Extended symmetry	Extended diagram	Order	Honeycombs
Pm3m (221)	4−:2	[4,3,4]		×1	1, 2, 3, 4, 5, 6
Fm3m (225)	2−:2	[1+,4,3,4] ↔ [4,31,1]	↔	Half	7, 11, 12, 13
I43m (217)	4o:2	[[(4,3,4,2+)]]		Half × 2	(7),
Fd3m (227)	2+:2	[[1+,4,3,4,1+]] ↔ [[3[4]]]	↔	Quarter × 2	10,
Im3m (229)	8o:2	[[4,3,4]]		×2	(1), 8, 9

[4,3,4], space group Pm3m (221)

Reference Indices	Honeycomb name Coxeter diagram and Schläfli symbol	Cell counts/vertex and positions in cubic honeycomb						Frames (Perspective)	Vertex figure	Dual cell
		(0)	(1)	(2)	(3)	Alt	Solids (Partial)
J11,15 A1 W1 G22 δ4	cubic (chon) t0{4,3,4} {4,3,4}				(8) (4.4.4)				octahedron	Cube,
J12,32 A15 W14 G7 O1	rectified cubic (rich) t1{4,3,4} r{4,3,4}	(2) (3.3.3.3)			(4) (3.4.3.4)				cuboid	Square bipyramid
J13 A14 W15 G8 t1δ4 O15	truncated cubic (tich) t0,1{4,3,4} t{4,3,4}	(1) (3.3.3.3)			(4) (3.8.8)				square pyramid	Isosceles square pyramid
J14 A17 W12 G9 t0,2δ4 O14	cantellated cubic (srich) t0,2{4,3,4} rr{4,3,4}	(1) (3.4.3.4)	(2) (4.4.4)		(2) (3.4.4.4)				oblique triangular prism	Triangular bipyramid
J17 A18 W13 G25 t0,1,2δ4 O17	cantitruncated cubic (grich) t0,1,2{4,3,4} tr{4,3,4}	(1) (4.6.6)	(1) (4.4.4)		(2) (4.6.8)				irregular tetrahedron	Triangular pyramidille
J18 A19 W19 G20 t0,1,3δ4 O19	runcitruncated cubic (prich) t0,1,3{4,3,4}	(1) (3.4.4.4)	(1) (4.4.4)	(2) (4.4.8)	(1) (3.8.8)				oblique trapezoidal pyramid	Square quarter pyramidille
J21,31,51 A2 W9 G1 hδ4 O21	alternated cubic (octet) h{4,3,4}				(8) (3.3.3)	(6) (3.3.3.3)			cuboctahedron	Dodecahedrille
J22,34 A21 W17 G10 h2δ4 O25	Cantic cubic (tatoh) ↔	(1) (3.4.3.4)			(2) (3.6.6)	(2) (4.6.6)			rectangular pyramid	Half oblate octahedrille
J23 A16 W11 G5 h3δ4 O26	Runcic cubic (sratoh) ↔	(1) (4.4.4)			(1) (3.3.3)	(3) (3.4.4.4)			tapered triangular prism	Quarter cubille
J24 A20 W16 G21 h2,3δ4 O28	Runcicantic cubic (gratoh) ↔	(1) (3.8.8)			(1) (3.6.6)	(2) (4.6.8)			Irregular tetrahedron	Half pyramidille
Nonuniformb	snub rectified cubic (serch) sr{4,3,4}	(1) (3.3.3.3.3)	(1) (3.3.3)		(2) (3.3.3.3.4)	(4) (3.3.3)			Irr. tridiminished icosahedron
Nonuniform	Cantic snub cubic (casch) 2s0{4,3,4}	(1) (3.3.3.3.3)			(2) (3.4.4.4)	(3) (3.4.4)
Nonuniform	Runcicantic snub cubic (rusch)	(1) (3.4.3.4)	(2) (4.4.4)	(1) (3.3.3)	(1) (3.6.6)	(3) Tricup
Nonuniform	Runcic cantitruncated cubic (esch) sr3{4,3,4}	(1) (3.3.3.3.4)	(1) (4.4.4)	(1) (4.4.4)	(1) (3.4.4.4)	(3) (3.4.4)

[[4,3,4]] honeycombs, space group Im3m (229)

Reference Indices	Honeycomb name Coxeter diagram and Schläfli symbol	Cell counts/vertex and positions in cubic honeycomb			Solids (Partial)	Frames (Perspective)	Vertex figure	Dual cell
		(0,3)	(1,2)	Alt
J11,15 A1 W1 G22 δ4 O1	runcinated cubic (same as regular cubic) (chon) t0,3{4,3,4}	(2) (4.4.4)	(6) (4.4.4)				octahedron	Cube
J16 A3 W2 G28 t1,2δ4 O16	bitruncated cubic (batch) t1,2{4,3,4} 2t{4,3,4}	(4) (4.6.6)					(disphenoid)	Oblate tetrahedrille
J19 A22 W18 G27 t0,1,2,3δ4 O20	omnitruncated cubic (gippich) t0,1,2,3{4,3,4}	(2) (4.6.8)	(2) (4.4.8)				irregular tetrahedron	Eighth pyramidille
J21,31,51 A2 W9 G1 hδ4 O27	Quarter cubic honeycomb (cytatoh) ht0ht3{4,3,4}	(2) (3.3.3)	(6) (3.6.6)				elongated triangular antiprism	Oblate cubille
J21,31,51 A2 W9 G1 hδ4 O21	Alternated runcinated cubic (octet) (same as alternated cubic) ht0,3{4,3,4}	(2) (3.3.3)	(6) (3.3.3)	(6) (3.3.3.3)			cuboctahedron
Nonuniform	Biorthosnub cubic honeycomb (gabreth) 2s0,3{(4,2,4,3)}	(2) (4.6.6)	(2) (4.4.4)	(2) (4.4.6)
Nonuniforma	Alternated bitruncated cubic (bisch) h2t{4,3,4}	(4) (3.3.3.3.3)		(4) (3.3.3)
Nonuniform	Cantic bisnub cubic (cabisch) 2s0,3{4,3,4}	(2) (3.4.4.4)	(2) (4.4.4)	(2) (4.4.4)
Nonuniformc	Alternated omnitruncated cubic (snich) ht0,1,2,3{4,3,4}	(2) (3.3.3.3.4)	(2) (3.3.3.4)	(4) (3.3.3)

B̃₃, [4,3^1,1] group

The ${\tilde {B}}_{3}$, [4,3] group offers 11 derived forms via truncation operations, four being unique uniform honeycombs. There are 3 index 2 subgroups that generate alternations: [1⁺,4,3^1,1], [4,(3^1,1)⁺], and [4,3^1,1]⁺. The first generates repeated honeycomb, and the last two are nonuniform but included for completeness.

The honeycombs from this group are called alternated cubic because the first form can be seen as a cubic honeycomb with alternate vertices removed, reducing cubic cells to tetrahedra and creating octahedron cells in the gaps.

Nodes are indexed left to right as 0,1,0',3 with 0' being below and interchangeable with 0. The alternate cubic names given are based on this ordering.

B3 honeycombs
Space group	Fibrifold	Extended symmetry	Extended diagram	Order	Honeycombs
Fm3m (225)	2−:2	[4,31,1] ↔ [4,3,4,1+]	↔	×1	1, 2, 3, 4
Fm3m (225)	2−:2	<[1+,4,31,1]> ↔ <[3[4]]>	↔	×2	(1), (3)
Pm3m (221)	4−:2	<[4,31,1]>		×2	5, 6, 7, (6), 9, 10, 11

[4,3^1,1] uniform honeycombs, space group Fm3m (225)

Referenced indices	Honeycomb name Coxeter diagrams	Cells by location (and count around each vertex)				Solids (Partial)	Frames (Perspective)	vertex figure
		(0)	(1)	(0')	(3)
J21,31,51 A2 W9 G1 hδ4 O21	Alternated cubic (octet) ↔			(6) (3.3.3.3)	(8) (3.3.3)			cuboctahedron
J22,34 A21 W17 G10 h2δ4 O25	Cantic cubic (tatoh) ↔	(1) (3.4.3.4)		(2) (4.6.6)	(2) (3.6.6)			rectangular pyramid
J23 A16 W11 G5 h3δ4 O26	Runcic cubic (sratoh) ↔	(1) cube		(3) (3.4.4.4)	(1) (3.3.3)			tapered triangular prism
J24 A20 W16 G21 h2,3δ4 O28	Runcicantic cubic (gratoh) ↔	(1) (3.8.8)		(2) (4.6.8)	(1) (3.6.6)			Irregular tetrahedron

<[4,3^1,1]> uniform honeycombs, space group Pm3m (221)

Referenced indices	Honeycomb name Coxeter diagrams ↔	Cells by location (and count around each vertex)				Solids (Partial)	Frames (Perspective)	vertex figure
		(0,0')	(1)	(3)	Alt
J11,15 A1 W1 G22 δ4 O1	Cubic (chon) ↔	(8) (4.4.4)						octahedron
J12,32 A15 W14 G7 t1δ4 O15	Rectified cubic (rich) ↔	(4) (3.4.3.4)		(2) (3.3.3.3)				cuboid
	Rectified cubic (rich) ↔	(2) (3.3.3.3)		(4) (3.4.3.4)				cuboid
J13 A14 W15 G8 t0,1δ4 O14	Truncated cubic (tich) ↔	(4) (3.8.8)		(1) (3.3.3.3)				square pyramid
J14 A17 W12 G9 t0,2δ4 O17	Cantellated cubic (srich) ↔	(2) (3.4.4.4)	(2) (4.4.4)	(1) (3.4.3.4)				obilique triangular prism
J16 A3 W2 G28 t0,2δ4 O16	Bitruncated cubic (batch) ↔	(2) (4.6.6)		(2) (4.6.6)				isosceles tetrahedron
J17 A18 W13 G25 t0,1,2δ4 O18	Cantitruncated cubic (grich) ↔	(2) (4.6.8)	(1) (4.4.4)	(1) (4.6.6)				irregular tetrahedron
J21,31,51 A2 W9 G1 hδ4 O21	Alternated cubic (octet) ↔	(8) (3.3.3)			(6) (3.3.3.3)			cuboctahedron
J22,34 A21 W17 G10 h2δ4 O25	Cantic cubic (tatoh) ↔	(2) (3.6.6)		(1) (3.4.3.4)	(2) (4.6.6)			rectangular pyramid
Nonuniforma	Alternated bitruncated cubic (bisch) ↔	(2) (3.3.3.3.3)		(2) (3.3.3.3.3)	(4) (3.3.3)
Nonuniformb	Alternated cantitruncated cubic (serch) ↔	(2) (3.3.3.3.4)	(1) (3.3.3)	(1) (3.3.3.3.3)	(4) (3.3.3)			Irr. tridiminished icosahedron

Ã₃, [3^[4]] group

There are 5 forms constructed from the ${\tilde {A}}_{3}$, [3^[4]] Coxeter group, of which only the quarter cubic honeycomb is unique. There is one index 2 subgroup [3^[4]]⁺ which generates the snub form, which is not uniform, but included for completeness.

A3 honeycombs
Space group	Fibrifold	Square symmetry	Extended symmetry	Extended diagram	Extended group	Honeycomb diagrams
F43m (216)	1o:2	a1	[3[4]]		${\tilde {A}}_{3}$	(None)
Fm3m (225)	2−:2	d2	<[3[4]]> ↔ [4,31,1]	↔	${\tilde {A}}_{3}$×21 ↔ ${\tilde {B}}_{3}$	1, 2
Fd3m (227)	2+:2	g2	[[3[4]]] or [2+[3[4]]]	↔	${\tilde {A}}_{3}$×22	3
Pm3m (221)	4−:2	d4	<2[3[4]]> ↔ [4,3,4]	↔	${\tilde {A}}_{3}$×41 ↔ ${\tilde {C}}_{3}$	4
I3 (204)	8−o	r8	[4[3[4]]]+ ↔ [[4,3+,4]]	↔	½${\tilde {A}}_{3}$×8 ↔ ½${\tilde {C}}_{3}$×2	(*)
Im3m (229)	8o:2		[4[3[4]]] ↔ [[4,3,4]]		${\tilde {A}}_{3}$×8 ↔ ${\tilde {C}}_{3}$×2	5

[[3^[4]]] uniform honeycombs, space group Fd3m (227)

Referenced indices	Honeycomb name Coxeter diagrams	Cells by location (and count around each vertex)		Solids (Partial)	Frames (Perspective)	vertex figure
		(0,1)	(2,3)
J25,33 A13 W10 G6 qδ4 O27	quarter cubic (cytatoh) ↔ q{4,3,4}	(2) (3.3.3)	(6) (3.6.6)			triangular antiprism

<[3^[4]]> ↔ [4,3^1,1] uniform honeycombs, space group Fm3m (225)

Referenced indices	Honeycomb name Coxeter diagrams ↔	Cells by location (and count around each vertex)			Solids (Partial)	Frames (Perspective)	vertex figure
		0	(1,3)	2
J21,31,51 A2 W9 G1 hδ4 O21	alternated cubic (octet) ↔ ↔ h{4,3,4}		(8) (3.3.3)	(6) (3.3.3.3)			cuboctahedron
J22,34 A21 W17 G10 h2δ4 O25	cantic cubic (tatoh) ↔ ↔ h2{4,3,4}	(2) (3.6.6)	(1) (3.4.3.4)	(2) (4.6.6)			Rectangular pyramid

[2[3^[4]]] ↔ [4,3,4] uniform honeycombs, space group Pm3m (221)

Referenced indices	Honeycomb name Coxeter diagrams ↔	Cells by location (and count around each vertex)		Solids (Partial)	Frames (Perspective)	vertex figure
		(0,2)	(1,3)
J12,32 A15 W14 G7 t1δ4 O1	rectified cubic (rich) ↔ ↔ ↔ r{4,3,4}	(2) (3.4.3.4)	(1) (3.3.3.3)			cuboid

[4[3^[4]]] ↔ [[4,3,4]] uniform honeycombs, space group Im3m (229)

Referenced indices	Honeycomb name Coxeter diagrams ↔ ↔	Cells by location (and count around each vertex)		Solids (Partial)	Frames (Perspective)	vertex figure
		(0,1,2,3)	Alt
J16 A3 W2 G28 t1,2δ4 O16	bitruncated cubic (batch) ↔ ↔ 2t{4,3,4}	(4) (4.6.6)				isosceles tetrahedron
Nonuniforma	Alternated cantitruncated cubic (bisch) ↔ ↔ h2t{4,3,4}	(4) (3.3.3.3.3)	(4) (3.3.3)

Nonwythoffian forms (gyrated and elongated)

Three more uniform honeycombs are generated by breaking one or another of the above honeycombs where its faces form a continuous plane, then rotating alternate layers by 60 or 90 degrees (gyration) and/or inserting a layer of prisms (elongation).

The elongated and gyroelongated alternated cubic tilings have the same vertex figure, but are not alike. In the elongated form, each prism meets a tetrahedron at one triangular end and an octahedron at the other. In the gyroelongated form, prisms that meet tetrahedra at both ends alternate with prisms that meet octahedra at both ends.

The gyroelongated triangular prismatic tiling has the same vertex figure as one of the plain prismatic tilings; the two may be derived from the gyrated and plain triangular prismatic tilings, respectively, by inserting layers of cubes.

Referenced indices	symbol	Honeycomb name	cell types (# at each vertex)	Solids (Partial)	Frames (Perspective)	vertex figure
J52 A2' G2 O22	h{4,3,4}:g	gyrated alternated cubic (gytoh)	tetrahedron (8) octahedron (6)			triangular orthobicupola
J61 A? G3 O24	h{4,3,4}:ge	gyroelongated alternated cubic (gyetoh)	triangular prism (6) tetrahedron (4) octahedron (3)
J62 A? G4 O23	h{4,3,4}:e	elongated alternated cubic (etoh)	triangular prism (6) tetrahedron (4) octahedron (3)
J63 A? G12 O12	{3,6}:g × {∞}	gyrated triangular prismatic (gytoph)	triangular prism (12)
J64 A? G15 O13	{3,6}:ge × {∞}	gyroelongated triangular prismatic (gyetaph)	triangular prism (6) cube (4)

Prismatic stacks

Eleven prismatic tilings are obtained by stacking the eleven uniform plane tilings, shown below, in parallel layers. (One of these honeycombs is the cubic, shown above.) The vertex figure of each is an irregular bipyramid whose faces are isosceles triangles.

The C̃₂×Ĩ₁(∞), [4,4,2,∞], prismatic group

There are only 3 unique honeycombs from the square tiling, but all 6 tiling truncations are listed below for completeness, and tiling images are shown by colors corresponding to each form.

Indices	Coxeter-Dynkin and Schläfli symbols	Honeycomb name	Plane tiling	Solids (Partial)	Tiling
J11,15 A1 G22	{4,4}×{∞}	Cubic (Square prismatic) (chon)	(4.4.4.4)
	r{4,4}×{∞}
	rr{4,4}×{∞}
J45 A6 G24	t{4,4}×{∞}	Truncated/Bitruncated square prismatic (tassiph)	(4.8.8)
	tr{4,4}×{∞}
J44 A11 G14	sr{4,4}×{∞}	Snub square prismatic (sassiph)	(3.3.4.3.4)
Nonuniform	ht0,1,2,3{4,4,2,∞}

The G̃₂xĨ₁(∞), [6,3,2,∞] prismatic group

Indices	Coxeter-Dynkin and Schläfli symbols	Honeycomb name	Plane tiling	Solids (Partial)	Tiling
J41 A4 G11	{3,6} × {∞}	Triangular prismatic (tiph)	(36)
J42 A5 G26	{6,3} × {∞}	Hexagonal prismatic (hiph)	(63)
	t{3,6} × {∞}
J43 A8 G18	r{6,3} × {∞}	Trihexagonal prismatic (thiph)	(3.6.3.6)
J46 A7 G19	t{6,3} × {∞}	Truncated hexagonal prismatic (thaph)	(3.12.12)
J47 A9 G16	rr{6,3} × {∞}	Rhombi-trihexagonal prismatic (srothaph)	(3.4.6.4)
J48 A12 G17	sr{6,3} × {∞}	Snub hexagonal prismatic (snathaph)	(3.3.3.3.6)
J49 A10 G23	tr{6,3} × {∞}	truncated trihexagonal prismatic (grothaph)	(4.6.12)
J65 A11' G13	{3,6}:e × {∞}	elongated triangular prismatic (etoph)	(3.3.3.4.4)
J52 A2' G2	h3t{3,6,2,∞}	gyrated tetrahedral-octahedral (gytoh)	(36)
	s2r{3,6,2,∞}
Nonuniform	ht0,1,2,3{3,6,2,∞}

Enumeration of Wythoff forms

All nonprismatic Wythoff constructions by Coxeter groups are given below, along with their alternations. Uniform solutions are indexed with Branko Grünbaum's listing. Green backgrounds are shown on repeated honeycombs, with the relations are expressed in the extended symmetry diagrams.

Coxeter group	Extended symmetry	Honeycombs		Chiral extended symmetry	Alternation honeycombs
[4,3,4]	[4,3,4]	6	22 | 7 | 8 9 | 25 | 20	[1+,4,3+,4,1+]	(2)	1 | b
	[2+[4,3,4]] =	(1)	22	[2+[(4,3+,4,2+)]]	(1)	1 | 6
	[2+[4,3,4]]	1	28	[2+[(4,3+,4,2+)]]	(1)	a
	[2+[4,3,4]]	2	27	[2+[4,3,4]]+	(1)	c
[4,31,1]	[4,31,1]	4	1 | 7 | 10 | 28
	[1[4,31,1]]=[4,3,4] =	(7)	22 | 7 | 22 | 7 | 9 | 28 | 25	[1[1+,4,31,1]]+	(2)	1 | 6 | a
				[1[4,31,1]]+ =[4,3,4]+	(1)	b
[3[4]]	[3[4]]	(none)
	[2+[3[4]]]	1	6
	[1[3[4]]]=[4,31,1] =	(2)	1 | 10
	[2[3[4]]]=[4,3,4] =	(1)	7
	[(2+,4)[3[4]]]=[2+[4,3,4]] =	(1)	28	[(2+,4)[3[4]]]+ = [2+[4,3,4]]+	(1)	a

Examples

The alternated cubic honeycomb is of special importance since its vertices form a cubic close-packing of spheres. The space-filling truss of packed octahedra and tetrahedra was apparently first discovered by Alexander Graham Bell and independently re-discovered by Buckminster Fuller (who called it the octet truss and patented it in the 1940s). [3] [4] [5] [6]. Octet trusses are now among the most common types of truss used in construction.

Frieze forms

If cells are allowed to be uniform tilings, more uniform honeycombs can be defined:

Families:

• ${\tilde {C}}_{2}$×$A_{1}$: [4,4,2] Cubic slab honeycombs (3 forms)
• ${\tilde {G}}_{2}$×$A_{1}$: [6,3,2] Tri-hexagonal slab honeycombs (8 forms)
• ${\tilde {A}}_{2}$×$A_{1}$: [(3,3,3),2] Triangular slab honeycombs (No new forms)
• ${\tilde {I}}_{1}$×$A_{1}$×$A_{1}$: [∞,2,2] = Cubic column honeycombs (1 form)
• $I_{2}(p)$×${\tilde {I}}_{1}$: [p,2,∞] Polygonal column honeycombs (analogous to duoprisms: these look like a single infinite tower of p-gonal prisms, with the remaining space filled with apeirogonal prisms)
• ${\tilde {I}}_{1}$×${\tilde {I}}_{1}$×$A_{1}$: [∞,2,∞,2] = [4,4,2] - = (Same as cubic slab honeycomb family)

Examples (partially drawn)

Cubic slab honeycomb	Alternated hexagonal slab honeycomb	Trihexagonal slab honeycomb
(4) 43: cube (1) 44: square tiling	(4) 33: tetrahedron (3) 34: octahedron (1) 36: triangular tiling	(2) 3.4.4: triangular prism (2) 4.4.6: hexagonal prism (1) (3.6)2: trihexagonal tiling

The first two forms shown above are semiregular (uniform with only regular facets), and were listed by Thorold Gosset in 1900 respectively as the 3-ic semi-check and tetroctahedric semi-check.

Scaliform honeycomb

A scaliform honeycomb is vertex-transitive, like a uniform honeycomb, with regular polygon faces while cells and higher elements are only required to be orbiforms, equilateral, with their vertices lying on hyperspheres. For 3D honeycombs, this allows a subset of Johnson solids along with the uniform polyhedra. Some scaliforms can be generated by an alternation process, leaving, for example, pyramid and cupola gaps.

Euclidean honeycomb scaliforms

Frieze slabs			Prismatic stacks
s3{2,6,3},	s3{2,4,4},	s{2,4,4},	3s4{4,4,2,∞},
(1) 3.4.3.4: triangular cupola (2) 3.4.6: triangular cupola (1) 3.3.3.3: octahedron (1) 3.6.3.6: trihexagonal tiling	(1) 3.4.4.4: square cupola (2) 3.4.8: square cupola (1) 3.3.3: tetrahedron (1) 4.8.8: truncated square tiling	(1) 3.3.3.3: square pyramid (4) 3.3.4: square pyramid (4) 3.3.3: tetrahedron (1) 4.4.4.4: square tiling	(1) 3.3.3.3: square pyramid (4) 3.3.4: square pyramid (4) 3.3.3: tetrahedron (4) 4.4.4: cube

Hyperbolic forms

The order-4 dodecahedral honeycomb, {5,3,4} in perspective

The paracompact hexagonal tiling honeycomb, {6,3,3}, in perspective

Main article: Uniform honeycombs in hyperbolic space

There are 9 Coxeter group families of compact uniform honeycombs in hyperbolic 3-space, generated as Wythoff constructions, and represented by ring permutations of the Coxeter-Dynkin diagrams for each family.

From these 9 families, there are a total of 76 unique honeycombs generated:

• [3,5,3] : - 9 forms
• [5,3,4] : - 15 forms
• [5,3,5] : - 9 forms
• [5,3^1,1] : - 11 forms (7 overlap with [5,3,4] family, 4 are unique)
• [(4,3,3,3)] : - 9 forms
• [(4,3,4,3)] : - 6 forms
• [(5,3,3,3)] : - 9 forms
• [(5,3,4,3)] : - 9 forms
• [(5,3,5,3)] : - 6 forms

Several non-Wythoffian forms outside the list of 76 are known; it is not known how many there are.

Paracompact hyperbolic forms

Main article: Paracompact uniform honeycombs

There are also 23 paracompact Coxeter groups of rank 4. These families can produce uniform honeycombs with unbounded facets or vertex figure, including ideal vertices at infinity:

Simplectic hyperbolic paracompact group summary

Type	Coxeter groups	Unique honeycomb count
Linear graphs	| | | | | |	4×15+6+8+8 = 82
Tridental graphs	| |	4+4+0 = 8
Cyclic graphs	| | | | | | | |	4×9+5+1+4+1+0 = 47
Loop-n-tail graphs	| | |	4+4+4+2 = 14

References

• John H. Conway, Heidi Burgiel, Chaim Goodman-Strauss, (2008) The Symmetries of Things, ISBN 978-1-56881-220-5 (Chapter 21, Naming the Archimedean and Catalan polyhedra and tilings, Architectonic and Catoptric tessellations, p 292–298, includes all the nonprismatic forms)
• Branko Grünbaum, (1994) Uniform tilings of 3-space. Geombinatorics 4, 49 - 56.
• Norman Johnson (1991) Uniform Polytopes, Manuscript
• Williams, Robert (1979). The Geometrical Foundation of Natural Structure: A Source Book of Design. Dover Publications, Inc. ISBN 0-486-23729-X. (Chapter 5: Polyhedra packing and space filling)
• Critchlow, Keith (1970). Order in Space: A design source book. Viking Press. ISBN 0-500-34033-1.
• 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, ISBN 978-0-471-01003-6 [7]
  • (Paper 22) H.S.M. Coxeter, Regular and Semi Regular Polytopes I, [Math. Zeit. 46 (1940) 380–407, MR 2,10] (1.9 Uniform space-fillings)
• A. Andreini, (1905) Sulle reti di poliedri regolari e semiregolari e sulle corrispondenti reti correlative (On the regular and semiregular nets of polyhedra and on the corresponding correlative nets), Mem. Società Italiana della Scienze, Ser.3, 14 75–129. PDF [8]
• D. M. Y. Sommerville, (1930) An Introduction to the Geometry of n Dimensions. New York, E. P. Dutton, . 196 pp. (Dover Publications edition, 1958) Chapter X: The Regular Polytopes
• Anthony Pugh (1976). Polyhedra: A visual approach. California: University of California Press Berkeley. ISBN 0-520-03056-7. Chapter 5. Joining polyhedra
• Crystallography of Quasicrystals: Concepts, Methods and Structures by Walter Steurer, Sofia Deloudi (2009), p. 54-55. 12 packings of 2 or more uniform polyhedra with cubic symmetry

External links

• Weisstein, Eric W. "Honeycomb". MathWorld.
• Uniform Honeycombs in 3-Space VRML models
• Elementary Honeycombs Vertex transitive space filling honeycombs with non-uniform cells.
• Uniform partitions of 3-space, their relatives and embedding, 1999
• The Uniform Polyhedra
• Virtual Reality Polyhedra The Encyclopedia of Polyhedra
• octet truss animation
• Review: A. F. Wells, Three-dimensional nets and polyhedra, H. S. M. Coxeter (Source: Bull. Amer. Math. Soc. Volume 84, Number 3 (1978), 466-470.)
• Klitzing, Richard. "3D Euclidean tesselations".
• (sequence A242941 in the OEIS)

Fundamental convex regular and uniform honeycombs in dimensions 2–9
Space	Family	${\tilde {A}}_{n-1}$	${\tilde {C}}_{n-1}$	${\tilde {B}}_{n-1}$	${\tilde {D}}_{n-1}$	${\tilde {G}}_{2}$ / ${\tilde {F}}_{4}$ / ${\tilde {E}}_{n-1}$
E2	Uniform tiling	0[3]	δ3	hδ3	qδ3	Hexagonal
E3	Uniform convex honeycomb	0[4]	δ4	hδ4	qδ4
E4	Uniform 4-honeycomb	0[5]	δ5	hδ5	qδ5	24-cell honeycomb
E5	Uniform 5-honeycomb	0[6]	δ6	hδ6	qδ6
E6	Uniform 6-honeycomb	0[7]	δ7	hδ7	qδ7	222
E7	Uniform 7-honeycomb	0[8]	δ8	hδ8	qδ8	133 • 331
E8	Uniform 8-honeycomb	0[9]	δ9	hδ9	qδ9	152 • 251 • 521
E9	Uniform 9-honeycomb	0[10]	δ10	hδ10	qδ10
E10	Uniform 10-honeycomb	0[11]	δ11	hδ11	qδ11
En-1	Uniform (n-1)-honeycomb	0[n]	δn	hδn	qδn	1k2 • 2k1 • k21