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  2. Centrosymmetry - Wikipedia

    en.wikipedia.org/wiki/Centrosymmetry

    In crystallography, a centrosymmetric point group contains an inversion center as one of its symmetry elements. [1] In such a point group, for every point (x, y, z) in the unit cell there is an indistinguishable point (-x, -y, -z). Such point groups are also said to have inversion symmetry. [2] Point reflection is a similar

  3. List of character tables for chemically important 3D point groups

    en.wikipedia.org/wiki/List_of_character_tables...

    For each non-linear group, the tables give the most standard notation of the finite group isomorphic to the point group, followed by the order of the group (number of invariant symmetry operations). The finite group notation used is: Z n : cyclic group of order n , D n : dihedral group isomorphic to the symmetry group of an n –sided regular ...

  4. Rod group - Wikipedia

    en.wikipedia.org/wiki/Rod_group

    In mathematics, a rod group is a three-dimensional line group whose point group is one of the axial crystallographic point groups. This constraint means that the point group must be the symmetry of some three-dimensional lattice. Table of the 75 rod groups, organized by crystal system or lattice type, and by their point groups:

  5. Point group - Wikipedia

    en.wikipedia.org/wiki/Point_group

    Point groups are used to describe the symmetries of geometric figures and physical objects such as molecules. Each point group can be represented as sets of orthogonal matrices M that transform point x into point y according to y = Mx. Each element of a point group is either a rotation (determinant of M = 1), or it is a reflection or improper ...

  6. Chirality - Wikipedia

    en.wikipedia.org/wiki/Chirality

    There are, however, achiral figures lacking both plane and center of symmetry. In terms of point groups, all chiral figures lack an improper axis of rotation (S n). This means that they cannot contain a center of inversion (i) or a mirror plane (σ). Only figures with a point group designation of C 1, C n, D n, T, O, or I can be chiral.

  7. List of space groups - Wikipedia

    en.wikipedia.org/wiki/List_of_space_groups

    The 54 hemisymmorphic space groups contain only axial combination of symmetry elements from the corresponding point groups. Example for point group 4/mmm (): hemisymmorphic space groups contain the axial combination 422, but at least one mirror plane m will be substituted with glide plane, for example P4/mcc (, 35h), P4/nbm (, 36h), P4/nnc ...

  8. Crystal system - Wikipedia

    en.wikipedia.org/wiki/Crystal_system

    The latter means, that enantiomorphic point groups describe chiral (enantiomorphic) structures. In the current table, "enantiomorphic" means that a group itself (considered as a geometric object) is enantiomorphic, like enantiomorphic pairs of three-dimensional space groups P3 1 and P3 2, P4 1 22 and P4 3 22. Starting from four-dimensional ...

  9. Template:Chembox PointGroup - Wikipedia

    en.wikipedia.org/wiki/Template:Chembox_PointGroup

    This template is used on many pages and changes may be widely noticed. Test changes in the template's /sandbox or /testcases subpages, or in your own user subpage . Consider discussing changes on the talk page before implementing them.