List of shapes with known packing constant

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Template:Short description The packing constant of a geometric body is the largest average density achieved by packing arrangements of congruent copies of the body. For most bodies the value of the packing constant is unknown.[1] The following is a list of bodies in Euclidean spaces whose packing constant is known.[1] Fejes Tóth proved that in the plane, a point symmetric body has a packing constant that is equal to its translative packing constant and its lattice packing constant.[2] Therefore, any such body for which the lattice packing constant was previously known, such as any ellipse, consequently has a known packing constant. In addition to these bodies, the packing constants of hyperspheres in 8 and 24 dimensions are almost exactly known.[3]

Image Description Dimension Packing constant Comments
Monohedral prototiles all 1 Shapes such that congruent copies can form a tiling of space
Circle, Ellipse 2 Template:Math Proof attributed to Thue[4]
Regular pentagon 2 5530.92131 Thomas Hales and Wöden Kusner[5]
Smoothed octagon 2 ηso=842ln22210.902414 Reinhardt[6]
All 2-fold symmetric convex polygons 2 Linear-time (in number of vertices) algorithm given by Mount and Ruth Silverman[7]
Sphere 3 Template:Math See Kepler conjecture
Bi-infinite cylinder 3 Template:Math Bezdek and Kuperberg[8]
Half-infinite cylinder 3 Template:Math Wöden Kusner[9]
All shapes contained in a rhombic dodecahedron whose inscribed sphere is contained in the shape 3 Fraction of the volume of the rhombic dodecahedron filled by the shape Corollary of Kepler conjecture. Examples pictured: rhombicuboctahedron and rhombic enneacontahedron.
Hypersphere 8 (π2)44!0.2536695 See Hypersphere packing[10][11]
Hypersphere 24 (π2)1212!0.000000471087 See Hypersphere packing

References

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