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 between, relation and/or order:

    You know there are no secrets in America. It’s quite different in England, where people think of a secret as a shared relation between two people.
    —W.H. (Wystan Hugh)

    Concord is just as idiotic as ever in relation to the spirits and their knockings. Most people here believe in a spiritual world ... in spirits which the very bullfrogs in our meadows would blackball. Their evil genius is seeing how low it can degrade them. The hooting of owls, the croaking of frogs, is celestial wisdom in comparison.
    Henry David Thoreau (1817–1862)

    Knowledge is and will be produced in order to be sold, it is and will be consumed in order to be valorized in a new production: in both cases, the goal is exchange. Knowledge ceases to be an end in itself, it loses its Use-value.
    Jean François Lyotard (b. 1924)