In particular, a symmetry element can be a mirror plane, an axis of rotation (either proper and improper), or a center of inversion. For an object such as a molecule or a crystal, a symmetry element corresponds to a set of symmetry operations, which are the rigid transformations employing the symmetry element that leave the object unchanged.
A symmetry element in particular can be a mirror plane, an axis of rotation (either proper or improper), or a center of inversion. For objects like molecules or crystals, this element corresponds to a set of symmetry operations that maintain the object’s unchanged state through rigid transformations involving the element.