As Point Group
Apart from the two infinite series of prismatic and antiprismatic symmetry, rotational icosahedral symmetry or chiral icosahedral symmetry of chiral objects and full icosahedral symmetry or achiral icosahedral symmetry are the discrete point symmetries (or equivalently, symmetries on the sphere) with the largest symmetry groups.
Icosahedral symmetry is not compatible with translational symmetry, so there are no associated crystallographic point groups or space groups.
| Schönflies crystallographic notation |
Coxeter notation |
Orbifold notation |
Order |
|---|---|---|---|
| I | + | 532 | 60 |
| Ih | *532 | 120 |
Presentations corresponding to the above are:
These correspond to the icosahedral groups (rotational and full) being the (2,3,5) triangle groups.
The first presentation was given by William Rowan Hamilton in 1856, in his paper on Icosian Calculus.
Note that other presentations are possible, for instance as an alternating group (for I).
Read more about this topic: Icosahedral Symmetry
Famous quotes containing the words point and/or group:
“It is sometimes a point of as much cleverness to know to make good use of advice from others as to be able give good advice to oneself.”
—François, Duc De La Rochefoucauld (1613–1680)
“Instead of seeing society as a collection of clearly defined “interest groups,” society must be reconceptualized as a complex network of groups of interacting individuals whose membership and communication patterns are seldom confined to one such group alone.”
—Diana Crane (b. 1933)