Symmetries of Canonical Polyhedra

Every polyhedron of genus zero has a unique canonical form which can be achieved by moving its vertices in such a way that its faces remain flat, the vertices themselves remain distinct, all of its edges are tangent to a common sphere, and the centroid of the edge tangency points is the center of that sphere. Besides being unique, the canonical form also brings out the maximum symmetry in a polyhedron. This is because any symmetry planes or axes in a non-canonical polyhedron are preserved in its canonical form [1].

To produce the table below, all 3-connected planar simple graphs with up to 12 vertices were generated using the plantri software developed by Gunnar Brinkmann and Brendan McKay. From each graph, a canonical polyhedron was produced and its symmetry determined. In canonical form, a polyhedron and its dual have the same symmetry, so the table shows the counts of all canonical polyhedra with up to 12 faces, cross tabulated by symmetry type and number of faces.

Symmetries of All Canonical Polyhedra with up to 12 Faces

Symmetry 4 faces 5 faces 6 faces 7 faces 8 faces 9 faces 10 faces 11 faces 12 faces TOTAL
C1 ...... ...... ...... 7 140 2111 30014 430494 6336013 6798779
Ci = S2 ...... ...... ...... ...... ...... ...... 7 ...... 201 208
Cs=C1h=C1v ...... ...... 1 11 67 365 1665 8424 40139 50672
C2 ...... ...... 1 4 22 80 427 1341 7290 9165
C3 ...... ...... ...... ...... ...... 1 8 11 29 49
C4 ...... ...... ...... ...... ...... ...... ...... ...... 1 1
C2h ...... ...... ...... ...... 1 ...... 17 ...... 110 128
C3h ...... ...... ...... ...... ...... ...... ...... ...... 2 2
C2v ...... ...... 2 6 13 34 108 248 669 1080
C3v ...... ...... ...... 4 2 5 31 29 40 111
C4v ...... 1 ...... ...... ...... 4 3 ...... 5 13
C5v ...... ...... 1 ...... ...... ...... ...... 4 3 8
C6v ...... ...... ...... 1 ...... ...... ...... ...... ...... 1
C7v ...... ...... ...... ...... 1 ...... ...... ...... ...... 1
C8v ...... ...... ...... ...... ...... 1 ...... ...... ...... 1
C9v ...... ...... ...... ...... ...... ...... 1 ...... ...... 1
C10v ...... ...... ...... ...... ...... ...... ...... 1 ...... 1
C11v ...... ...... ...... ...... ...... ...... ...... ...... 1 1
S4 ...... ...... ...... ...... ...... ...... 1 ...... 20 21
D2 ...... ...... ...... ...... ...... ...... 5 ...... 47 52
D3 ...... ...... ...... ...... ...... ...... ...... 1 4 5
D2h ...... ...... ...... ...... 1 ...... 3 ...... 12 16
D3h ...... 1 1 ...... 1 4 ...... 10 8 25
D4h ...... ...... ...... ...... ...... ...... 1 ...... 3 4
D5h ...... ...... ...... 1 ...... ...... 1 ...... 1 3
D6h ...... ...... ...... ...... 1 ...... ...... ...... 1 2
D7h ...... ...... ...... ...... ...... 1 ...... ...... ...... 1
D8h ...... ...... ...... ...... ...... ...... 1 ...... ...... 1
D9h ...... ...... ...... ...... ...... ...... ...... 1 ...... 1
D10h ...... ...... ...... ...... ...... ...... ...... ...... 1 1
D2v ...... ...... ...... ...... 4 ...... 3 ...... 22 29
D3v ...... ...... ...... ...... 1 ...... ...... ...... 7 8
D4v ...... ...... ...... ...... 1 ...... 2 ...... ...... 3
D5v ...... ...... ...... ...... ...... ...... 1 ...... 1 2
D6v ...... ...... ...... ...... ...... ...... ...... ...... 1 1
T ...... ...... ...... ...... ...... ...... ...... ...... ...... ......
Td 1 ...... ...... ...... 1 ...... 1 ...... 1 4
Th ...... ...... ...... ...... ...... ...... ...... ...... ...... ......
O ...... ...... ...... ...... ...... ...... ...... ...... ...... ......
Oh ...... ...... 1 ...... 1 ...... ...... ...... 1 3
I ...... ...... ...... ...... ...... ...... ...... ...... ...... ......
Ih ...... ...... ...... ...... ...... ...... ...... ...... 1 1
TOTAL 1 2 7 34 257 2606 32300 440564 6384634 6860405
non-C1 1 2 7 27 117 495 2286 10070 48621 61626

References:[1]Canonical Polyhedron (Wolfram MathWorld)
[2]Gunnar Brinkmann and Brendan D. McKay, Fast generation of planar graphs, MATCH-Communications in Mathematical and in Computer Chemistry 58(2) (2007), 323-357.