Point Groups in Three Dimensions - Relation Between Orbifold Notation and Order

Relation Between Orbifold Notation and Order

The order of each group is 2 divided by the orbifold Euler characteristic; the latter is 2 minus the sum of the feature values, assigned as follows:

  • n without or before * counts as (n−1)/n
  • n after * counts as (n−1)/(2n)
  • * and x count as 1

This can also be applied for wallpaper groups and frieze groups: for them, the sum of the feature values is 2, giving an infinite order; see orbifold Euler characteristic for wallpaper groups

Read more about this topic:  Point Groups In Three Dimensions

Famous quotes containing the words relation and/or order:

    “Art should exhilarate, and throw down the walls of circumstance on every side, awakening in the beholder the same sense of universal relation and power which the work evinced in the artist, and its highest effect is to make new artists.”
    —Ralph Waldo Emerson (1803–1882)

    “We have created an industrial order geared to automatism, where feeble-mindedness, native or acquired, is necessary for docile productivity in the factory; and where a pervasive neurosis is the final gift of the meaningless life that issues forth at the other end.”
    —Lewis Mumford (1895–1990)