Activation energies for the motion of interstitials, vacancies and vacancy clusters were calculated by using embedded atom potentials. The most striking results which were obtained were that the stable interstitial configuration was a [100] split type, and that the saddle point was a body-centered interstitial. This was quite contrary to widely accepted computational results. The atom above the center of a 60º tri-vacancy relaxed to the center of the tetrahedron in Cu but did not relax to the center of the tetrahedron in Ag. In the case of Au, the energy gain in relaxing to the center was very small and the atoms tended to move around in the tetrahedron. The details depended upon the potentials used.

Computer Simulation of Point Defects in FCC Metals using EAM Potentials. N.Tajima, O.Takai, Y.Kogure, M.Doyama: Computational Materials Science, 1999, 14[1-4], 152-8