The Ci point groupCi carries 2 symmetry operations in 2 classes, and no axis of rotation above the identity. A character table of the group therefore has 2 columns and as many irreducible representations.It contains an improper operation, so no molecule in it is chiral. No direction is left invariant, so a molecule in it has no permanent dipole. It contains the inversion, so its vibrations and its electronic states divide into g and u, and no vibration is both infrared and Raman active.In Hermann-Mauguin notation it is -1, and it is one of the crystal classes of the triclinic system. A diffraction pattern from a crystal in it shows the Laue symmetry -1.

anti meso-1,2-dichloro-1,2-difluoroethane (C2H2F2Cl2): The anti conformer maps onto itself only through the C–C midpoint.

The 2 conjugacy classes of Ci, in the order a character table prints them.

Class

Operations in it

Molecular point groups with their operations and character tables, the 230 space groups with a cell builder, and the 17 wallpaper and 7 frieze groups drawn live. The tool needs JavaScript, and WebGL2 for the 3D views; these are the pages it offers: