BornOppenheimerolettaman

BornOppenheimerolettaman is a fictional framework used in quantum chemistry to illustrate a hypothetical extension of the Born–Oppenheimer approximation. The term combines the classic separation of electronic and nuclear motion with a speculative correction scheme attributed to a fictional researcher, Oletta Man, sometimes stylized as Olettaman. In this imagined approach, the standard adiabatic picture is augmented by an explicit treatment of non-adiabatic couplings through a dedicated operator and a unified nuclear Hamiltonian.

The core idea is to retain the efficiency of the Born–Oppenheimer separation while incorporating electronic–nuclear interactions that become important near regions where potential energy surfaces approach each other, such as conical intersections. Proponents envision an effective Hamiltonian for nuclei that carries electronic-state indices, allowing simultaneous description of multiple surfaces and their couplings within a single formalism.

In practice, a hypothetical workflow would involve computing electronic states at fixed nuclear geometries, constructing non-adiabatic coupling vectors, applying the olettaman corrections, and solving the nuclear motion on coupled surfaces. Techniques commonly discussed alongside this concept include multi-surface dynamics and surface-hopping schemes, adapted to the olettaman framework in this fictional setting.

Although BornOppenheimerolettaman is not part of established literature, it is sometimes cited in teaching as a conceptual tool for exploring the limitations of adiabatic approximations and the ongoing need for methods that treat electronic and nuclear degrees of freedom on a more unified footing.