Hexagonal tiling

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Hexagonal tiling
Hexagonal tiling
Type
Regular tiling
Vertex configuration 6.6.6 (or 63)
Face configuration
V3.3.3.3.3.3 (or V36)
Schläfli symbol(s) {6,3}
t{3,6}
Wythoff symbol(s) 3 | 6 2
2 6 | 3
3 3 3 |
Coxeter diagram(s)

Symmetry
p6m
, [6,3], (*632)
Rotation symmetry
p6
, [6,3]+, (632)
Dual Triangular tiling
Properties
face-transitive

In

regular tiling of the Euclidean plane, in which exactly three hexagons meet at each vertex. It has Schläfli symbol of {6,3} or t{3,6} (as a truncated
triangular tiling).

English mathematician John Conway called it a hextille.

The

internal angle of the hexagon is 120 degrees, so three hexagons at a point make a full 360 degrees. It is one of three regular tilings of the plane. The other two are the triangular tiling and the square tiling
.

Applications

Hexagonal tiling is the densest way to

body-centered cubic lattice) is optimal. However, the less regular Weaire–Phelan structure
is slightly better.

This structure exists naturally in the form of

tensile strength and electrical properties. Silicene
is similar.

Chicken wire consists of a hexagonal lattice (often not regular) of wires.

The hexagonal tiling appears in many crystals. In three dimensions, the

hexagonal close packing are common crystal structures. They are the densest sphere packings in three dimensions. Structurally, they comprise parallel layers of hexagonal tilings, similar to the structure of graphite. They differ in the way that the layers are staggered from each other, with the face-centered cubic being the more regular of the two. Pure copper
, amongst other materials, forms a face-centered cubic lattice.

Uniform colorings

There are three distinct

Goldberg polyhedra
, with a notation {p+,3}h,k, and can be applied to hyperbolic tilings for p > 6.

k-uniform 1-uniform 2-uniform 3-uniform
Symmetry p6m, (*632) p3m1, (*333) p6m, (*632) p6, (632)
Picture
Colors 1 2 3 2 4 2 7
(h,k) (1,0) (1,1) (2,0) (2,1)
Schläfli {6,3} t{3,6} t{3[3]}
Wythoff 3 | 6 2 2 6 | 3 3 3 3 |
Coxeter
Conway H cH=t6daH wH=t6dsH

The 3-color tiling is a tessellation generated by the order-3 permutohedrons.

Chamfered hexagonal tiling

A

rhombic tiling
.

The chamfered hexagonal tiling degenerates into a rhombille tiling at the limit
Hexagons (H) Chamfered hexagons (cH) Rhombi (daH)

Related tilings

The hexagons can be dissected into sets of 6 triangles. This process leads to two

2-uniform tilings, and the triangular tiling
:

Regular tiling Dissection
2-uniform tilings
Regular tiling Inset Dual Tilings

Original

1/3 dissected

2/3 dissected

fully dissected

E to IH to FH to H

The hexagonal tiling can be considered an elongated rhombic tiling, where each vertex of the rhombic tiling is stretched into a new edge. This is similar to the relation of the

rhombo-hexagonal dodecahedron
tessellations in 3 dimensions.


Rhombic tiling

Hexagonal tiling

Fencing uses this relation

It is also possible to subdivide the prototiles of certain hexagonal tilings by two, three, four or nine equal pentagons:


Pentagonal tiling type 1 with overlays of regular hexagons (each comprising 2 pentagons).

pentagonal tiling type 3 with overlays of regular hexagons (each comprising 3 pentagons).

Pentagonal tiling type 4 with overlays of semiregular hexagons (each comprising 4 pentagons).

Pentagonal tiling type 3 with overlays of two sizes of regular hexagons (comprising 3 and 9 pentagons respectively).

Symmetry mutations

This tiling is topologically related as a part of a sequence of regular tilings with

Coxeter diagram
, progressing to infinity.

*n62 symmetry mutation of regular tilings: {6,n}
Spherical Euclidean Hyperbolic tilings

{6,2}

{6,3}

{6,4}

{6,5}

{6,6}

{6,7}

{6,8}
...
{6,∞}

This tiling is topologically related to regular polyhedra with vertex figure n3, as a part of a sequence that continues into the hyperbolic plane.

*n32 symmetry mutation of regular tilings: {n,3}
Spherical
Euclidean
Compact hyperb. Paraco. Noncompact hyperbolic
{2,3} {3,3} {4,3} {5,3} {6,3} {7,3} {8,3} {∞,3} {12i,3} {9i,3} {6i,3} {3i,3}

It is similarly related to the uniform truncated polyhedra with vertex figure n.6.6.

*n32 symmetry mutation of truncated tilings: n.6.6
Sym.
*n42
[n,3]
Spherical Euclid. Compact Parac. Noncompact hyperbolic
*232
[2,3]
*332
[3,3]
*432
[4,3]
*532
[5,3]
*632
[6,3]
*732
[7,3]
*832
[8,3]...
*∞32
[∞,3]
[12i,3] [9i,3] [6i,3]
Truncated
figures
Config. 2.6.6 3.6.6 4.6.6 5.6.6 6.6.6 7.6.6 8.6.6 ∞.6.6 12i.6.6 9i.6.6 6i.6.6
n-kis
figures
Config.
V2.6.6 V3.6.6 V4.6.6 V5.6.6
V6.6.6
V7.6.6 V8.6.6 V∞.6.6 V12i.6.6 V9i.6.6 V6i.6.6

This tiling is also part of a sequence of truncated rhombic polyhedra and tilings with [n,3] Coxeter group symmetry. The cube can be seen as a rhombic hexahedron where the rhombi are squares. The truncated forms have regular n-gons at the truncated vertices, and nonregular hexagonal faces.

Symmetry mutations of dual quasiregular tilings: V(3.n)2
*n32 Spherical Euclidean Hyperbolic
*332 *432 *532 *632 *732 *832... *∞32
Tiling
Conf.
V(3.3)2 V(3.4)2 V(3.5)2 V(3.6)2 V(3.7)2 V(3.8)2 V(3.∞)2

Wythoff constructions from hexagonal and triangular tilings

Like the uniform polyhedra there are eight uniform tilings that can be based on the regular hexagonal tiling (or the dual triangular tiling).

Drawing the tiles colored red on the original faces, yellow at the original vertices, and blue along the original edges, there are 8 forms, 7 of which are topologically distinct. (The truncated triangular tiling is topologically identical to the hexagonal tiling.)

Uniform hexagonal/triangular tilings
Fundamental
domains
Symmetry: [6,3], (*632) [6,3]+, (632)
{6,3} t{6,3} r{6,3} t{3,6} {3,6} rr{6,3} tr{6,3} sr{6,3}
Config. 63 3.12.12 (6.3)2 6.6.6 36 3.4.6.4 4.6.12 3.3.3.3.6

Monohedral convex hexagonal tilings

There are 3 types of monohedral convex hexagonal tilings.[1] They are all isohedral. Each has parametric variations within a fixed symmetry. Type 2 contains glide reflections, and is 2-isohedral keeping chiral pairs distinct.

3 types of monohedral convex hexagonal tilings
1 2 3
p2, 2222 pgg, 22× p2, 2222 p3, 333

b = e
B + C + D = 360°

b = e, d = f
B + C + E = 360°

a = f, b = c, d = e
B = D = F = 120°

2-tile lattice

4-tile lattice

3-tile lattice

Topologically equivalent tilings

Hexagonal tilings can be made with the identical {6,3} topology as the regular tiling (3 hexagons around every vertex). With isohedral faces, there are 13 variations. Symmetry given assumes all faces are the same color. Colors here represent the lattice positions.[2] Single-color (1-tile) lattices are parallelogon hexagons.

13 isohedrally-tiled hexagons
pg (××) p2 (2222) p3 (333) pmg (22*)
pgg (22×) p31m (3*3) p2 (2222) cmm (2*22) p6m (*632)

Other isohedrally-tiled topological hexagonal tilings are seen as quadrilaterals and pentagons that are not edge-to-edge, but interpreted as colinear adjacent edges:

Isohedrally-tiled quadrilaterals
pmg (22*) pgg (22×) cmm (2*22) p2 (2222)

Parallelogram

Trapezoid

Parallelogram

Rectangle

Parallelogram

Rectangle

Rectangle
Isohedrally-tiled pentagons
p2 (2222) pgg (22×) p3 (333)

The 2-uniform and 3-uniform tessellations have a rotational degree of freedom which distorts 2/3 of the hexagons, including a colinear case that can also be seen as a non-edge-to-edge tiling of hexagons and larger triangles.[3]

It can also be distorted into a chiral 4-colored tri-directional weaved pattern, distorting some hexagons into parallelograms. The weaved pattern with 2 colored faces has rotational 632 (p6) symmetry. A chevron pattern has pmg (22*) symmetry, which is lowered to p1 (°) with 3 or 4 colored tiles.

Regular Gyrated Regular Weaved Chevron
p6m, (*632) p6, (632) p6m (*632) p6 (632) p1 (°)
p3m1, (*333) p3, (333) p6m (*632) p2 (2222) p1 (°)

Circle packing

The hexagonal tiling can be used as a circle packing, placing equal-diameter circles at the center of every point. Every circle is in contact with 3 other circles in the packing (kissing number).[4] The gap inside each hexagon allows for one circle, creating the densest packing from the triangular tiling, with each circle in contact with a maximum of 6 circles.

Related regular complex apeirogons

There are 2

regular complex apeirogons, sharing the vertices of the hexagonal tiling. Regular complex apeirogons have vertices and edges, where edges can contain 2 or more vertices. Regular apeirogons p{q}r are constrained by: 1/p + 2/q + 1/r = 1. Edges have p vertices, and vertex figures are r-gonal.[5]

The first is made of 2-edges, three around every vertex, the second has hexagonal edges, three around every vertex. A third complex apeirogon, sharing the same vertices, is quasiregular, which alternates 2-edges and 6-edges.

2{12}3 or 6{4}3 or

See also

References

  1. ^ Tilings and patterns, Sec. 9.3 Other Monohedral tilings by convex polygons
  2. ^ Tilings and patterns, from list of 107 isohedral tilings, pp. 473–481
  3. ^ Tilings and patterns, uniform tilings that are not edge-to-edge
  4. ^ Order in Space: A design source book, Keith Critchlow, pp. 74–75, pattern 2
  5. ^ Coxeter, Regular Complex Polytopes, pp. 111–112, p. 136.

External links

Space Family / /
E2 Uniform tiling {3[3]} δ3 3 3 Hexagonal
E3
Uniform convex honeycomb
{3[4]} δ4 4 4
E4
Uniform 4-honeycomb
{3[5]} δ5 5 5 24-cell honeycomb
E5
Uniform 5-honeycomb
{3[6]} δ6 6 6
E6
Uniform 6-honeycomb
{3[7]} δ7 7 7 222
E7
Uniform 7-honeycomb
{3[8]} δ8 8 8 133331
E8
Uniform 8-honeycomb
{3[9]} δ9 9 9 152251521
E9
Uniform 9-honeycomb
{3[10]} δ10 10 10
E10 Uniform 10-honeycomb {3[11]} δ11 11 11
En-1 Uniform (n-1)-honeycomb
{3[n]}
δn n n 1k22k1k21