glSyMM pretends to be a point symmetry display system. Its main purpose is to identify (using as back-end SyMM) the point group of a molecule and to perform the symmetry operations on the molecule.

- Inversion on the symmetry center: atoms move from a position the
"inverted" position (x,y,z) --> (-x,-y,-z)

- Rotation around one axis; the axis is drawn and the rotation occurs.

- Reflection on a mirror plane.

- Improper rotation: a combination of the above two operations