A functionally flexible interatomic energy function based on classical potentials

A flexible potential energy function is proposed herein on the basis of classical potential functions of Lennard-Jones, Morse, Buckingham and Linnett. By introducing two indices, which range from 0 to 1, the proposed function can either be reduced to the classical potentials by fixing the indices at their extremes or be used as a flexible function for curve-fitting interatomic energy data over a broad range of interatomic distance. In a departure from previous effort that give exact parametric relationships only at the minimum well-depth, the present paper quantitatively accounts for the discrepancies at very large interatomic compression and stretching.