Molecular dynamics techniques were used to study the properties of self-interstitials using semi-empirical many-body potentials that were based on the embedded atom method. A set of values of formation, binding and migration energies were calculated for single, di-, tri-, tetra-, penta- and hexa-interstitials. The results showed that small interstitial clusters had a significantly lower migration energy than that of single interstitials, and moved in the form of 1-dimensional crowdions. The clusters in Cu were very mobile but the tri- and penta-interstitials in Ni were less mobile because they were difficult to relax to the crowdion dumb-bell configurations.

Molecular Dynamics Calculations of Properties of Self-Interstitials in Copper and Nickel. P.Zhao, Y.Shimomura: Computational Materials Science, 1999, 14[1-4], 84-90