The properties of a lattice defect, which was formed by the incomplete recombination of a vacancy-interstitial pair, were described by combining tight-binding molecular dynamics and  ab initio  Hartree-Fock calculations. The defect structure consisted of a large nuclear distortion which was almost perfectly compensated by electron-charge rearrangement. The reaction path for its annihilation was described in terms of an electron-density topological analysis within the quantum theory of atoms in molecules approach. An electron-density analysis indicated that, in the bond-defect complex, some 0.5 electrons were subtracted from the defective atoms and transferred to the surroundings. This charge leakage persisted over the bond-defect annihilation path.

F.Cargnoni, C.Gatti, L.Colombo: Physical Review B, 1998, 57[1], 170-7