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)

    There is a certain standard of grace and beauty which consists in a certain relation between our nature, such as it is, weak or strong, and the thing which pleases us. Whatever is formed according to this standard pleases us, be it house, song, discourse, verse, prose, woman, birds, rivers, trees, room, dress, and so on. Whatever is not made according to this standard displeases those who have good taste.
    Blaise Pascal (1623–1662)

    Deafness produces bizarre effects, reversing the natural order of things; the interchange of letters is the conversation of the deaf, and the only link with society. I would be in despair, for instance, over seeing you speak, but, instead, I am only too happy to hear you write.
    Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)