On the physical meaning of the molecular point group

It is argued that the most important result of applying the Born–Oppenheimer approximation to intramolecular dynamics is not the separation of electron and nuclear motions but the transition to the problem formulation in which the symmetry properties of the point group transformations characterizing a molecule in a chosen electron state can be correctly taken into account. It is shown that this group should be used as a rigorous symmetry group of total (electron–vibration–rotational) motion in this state.