three-fold rotation axis
1Point groups in three dimensions — In geometry, a point group in three dimensions is an isometry group in three dimensions that leaves the origin fixed, or correspondingly, an isometry group of a sphere. It is a subgroup of the orthogonal group O(3), the group of all isometries… …
2Dihedral symmetry in three dimensions — This article deals with three infinite sequences of point groups in three dimensions which have a symmetry group that as abstract group is a dihedral group Dihn ( n ≥ 2 ). See also point groups in two dimensions. Chiral: Dn (22n) of… …
3Screw axis — The screw axis (helical axis or twist axis) of an object is a parameter for describing simultaneous rotation and translation components of that object.The axis is a directed line in space, along which a translation may occur, and about which… …
4Molecular symmetry — in chemistry describes the symmetry present in molecules and the classification of molecules according to their symmetry. Molecular symmetry is a fundamental concept in chemistry, as it can predict or explain many of a molecule s chemical… …
5Polyhedral symbol — The polyhedral symbol is sometimes used in coordination chemistry to indicate the approximate geometry of the coordinating atoms around the central atom. One or more italicised letters indicate the geometry, e.g. TP 3 which is followed by a… …
6Island Three — For fictional structures for living in space, see Space stations and habitats in popular culture. Artist s depiction of a pair of O Neill cylinders. The O Neill cylinder (also called an Island Three habitat) is a space settlement design proposed… …
7Crystallographic point group — In crystallography, a crystallographic point group is a set of symmetry operations, like rotations or reflections, that leave a central point fixed while moving other directions and faces of the crystal to the positions of features of the same… …
8Dihedral group of order 6 — The smallest non abelian group has 6 elements. It is a dihedral group with notation D3 (or D6, both are used) and the symmetric group of degree 3, with notation S3. This page illustrates many group concepts using this group as example. Contents 1 …
9Schoenflies notation — The Schoenflies notation is one of two conventions commonly used to describe crystallographic point groups. This notation is used in spectroscopy. The other convention is the Hermann Mauguin notation, also known as the International notation. A… …
10Crystal system — Diamond crystal structure consists of face centered cubic lattice. In crystallography, the terms crystal system, crystal family, and lattice system each refer to one of several classes of space groups, lattices, point groups, or crystals.… …
