Relation between the shear and dilatational elastic energies of interstitial defects in metallic crystals

Molecular statics simulation of interstitial defects for four metals with a face-centered cubic lattice has been carried out. The volumes of Voronoi polyhedra are calculated for defect-forming atoms and their nearest environment. These calculations indicate that the ratio of the dilatational to shear contribution to the elastic energy for the most stable split interstitials does not exceed 0.12-0.13. The validity of the same conclusion for dumbbell interstitial defects in metallic glasses is argued.