Simulation for mechanical relaxation and interaction of point defects

A molecular dynamics computer simulation for self-interstitials in copper crystals has been performed by using the embedded atom method potential functions. Configuration and stress distribution around an interstitial are calculated. Interaction energy between two interstitials for parallel and perpendicular configuration is calculated as a function of distance. Thermal vibration and migration of dipole are also investigated by a simulation at a constant temperature, 300 K. The time evolution of the atomic displacement and the power spectra are calculated. A large unstable motion of interstitial atoms in split direction is observed when the interstitial migrate. The method can be applied to the simulation of complex relaxation.