Miquel configuration
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In geometry, the Miquel configuration is a configuration of eight points and six circles in the Euclidean plane, (83 64), with four points per circle and three circles through each point.[1]
Its Levi graph is the rhombic dodecahedral graph, the skeleton of the rhombic dodecahedron. The configuration is related to Miquel's theorem.
The Miquel configuration drawn with equal diameter circles
The configuration drawn with square symmetry
The Levi graph of the Miquel configuration. 6 blue vertices from circles, and 8 red vertices from points.
In three dimensions
The configuration has maximal symmetry in 3-dimension, and can be seen as 6 circles circumscribe the square faces of a cube. It has 12 sets of pairwise circle intersections, corresponding to the edges of the cube and octahedron. Structurally it has 48 automorphisms of octahedral symmetry.
If two opposite circles are removed the configuration becomes (82 42), with 128 automorphisms (4 rotations by 23 pair interchanges)
A different (83 64) can be found as with 6 central circles on a cube. The circles are on the 6 mirror planes of tetrahedral symmetry. In full it has 384 automorphisms of hyperoctahedral symmetry as the maximal geometric symmetry can be seen in 6, C(4,2), orthogonal circles as central squares in a 16-cell.
| Miquel 6-circle | Reduced 4-circle | Reduced & doubled 8-circle | Miquel+Central 12-circle | Central 6-circle |
|---|---|---|---|---|
| (83 64) | (82 44) | (84) | (86 124) | (83 64) |
| 48 Aut (3!×23) | 128 Aut (4×23) | 192 Aut (4!×23) | 384 Aut (4!×24) | |
 6 circles 8 vertices of cube |
 4 circles on 8 vertices of cube |
 8 circles (4 central) on 8 vertices of cube |
 12 circles (6 central) on 8 vertices of cube |
 6 central circles on 8 vertices on a cube |
