The diagonal Born–Oppenheimer correction to molecular dynamical properties

We examine the effect of the diagonal Born–Oppenheimer correction on dynamics in two simple systems – the Hookeʹs atom in an external harmonic potential and the collinear hydrogen exchange reaction. The transmission probability for the Hookeʹs atom, calculated within the Born–Oppenheimer approximation, is simply shifted in energy with respect to the exact result, and this is corrected by the diagonal adiabatic contribution. The reaction probability for the H3 system reflects the fact, that the diagonal Born–Oppenheimer correction raises the barrier to the reaction by approximately 70 cm−1.