Distributed approximating functional approach to fitting and predicting potential surfaces. 1. Atom-atom potentials

A procedure is presented for obtaining an analytical representation of the potential energy for a diatomic system, knowing the potential only at finite number of internuclear separations. The approach is based on the distributed approximating functional (DAF), which has the property of delivering comparable accuracy for approximating a function and its derivatives, given such limited input data. The method is illustrated by applications to several atom-atom potentials, including those for the Li2 and H2 systems.