On the physical meaning of the molecular point group
Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, ul. Ulyanova 46, Nizhny Novgorod, 603000, Russian Federation
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.