An empirical interaction potential was developed; mainly for the simulation of displacement cascades in an urania matrix. A bibliographical survey revealed that the potentials used in the literature were not completely suitable for describing point defects

and their migration. It was decided to adapt the most representative of the existing potentials, with the specific aim of reproducing the transport phenomena which were fundamental to the satisfactory description of atomic displacement cascades. This modified potential reproduced the experimental energies of formation and migration of point defects more correctly, as well as O diffusion coefficients in the superionic phase. The new potential was far more transferable than were earlier potentials; which were fitted mainly to the properties of perfect crystals. Some initial simulated atomic displacement cascades showed that the potential was well-suited to the description of structural damage caused by decelerating recoil nuclei in an urania matrix.

A New Empirical Potential for Simulating the Formation of Defects and their Mobility in Uranium Dioxide. N.D.Morelon, D