Beyond the born-oppenheimer approximation

In this review we discuss how one can approach atomic and molecular quantum-mechanical calculations without assuming the clamp-nuclei approximation. Although such calculations are very rare for chemically interesting systems, the progress in conceptual formulation of the theory in this area and, more importantly, in development of necessary computational tool has progressed to the point where non-Born-Oppenheimer it will completely undermine, traditional approaches to the problems of molecular spectroscopy which are based on the concept of the Potential Energy Surface (PES). It may also provide new insight in such important concepts of chemistry as Chemical Bonding and Molecular Structure, which have been the central points in the works of L. Pauling [1].