Inversion symmetry (2D)

Two-dimensional inversion symmetry, also know as essic symmetry or chiral digonal symmetry and notated as K2+, is a 2D spherical symmetry group. It is the symmetry group of the parallelogram and corresponds to central inversion symmetry. It can be considered the digonal member of the family of chiral polygonal symmetries. It is a subsymmetry of any even polygonal symmetry.

Subgroups

 * I×I (maximal)