Scaling the reaction path potential

A molecular potential energy surface may be approximately described in terms of the energy, energy gradients, and second derivatives at a discrete set of points along a reaction path. The accuracy of this approach is limited, in part, by the level of ab initio theory that can be employed to obtain energy gradients and second derivatives. A method is derived and demonstrated whereby the energy surface can be scaled to achieve a greater degree of accuracy, using a set of energies calculated at a higher level of ab initio theory.