The C∞v point groupC∞v is one of the two linear point groups: its principal axis is of infinite order, so it carries infinitely many symmetry operations in 3 classes.It contains an improper operation, so no molecule in it is chiral. It leaves a direction invariant, so a molecule in it may carry a permanent dipole.

Hydrogen chloride (HCl): Two different atoms on a line: no centre to invert through.

Hydrogen cyanide (HCN): Linear and read differently from each end.

Carbonyl sulfide (OCS): Carbon dioxide with one oxygen swapped: the inversion centre goes.

The 3 conjugacy classes of C∞v, in the order a character table prints them.

Class

Operations in it

2C∞

∞σv

infinitely many

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: