Molecular-dynamics studies of self-interstitial aggregates in Si

The interactions between neutral self-interstitials in silicon are studied using ab initio tight-binding molecular-dynamics simulations in periodic supercells containing 64 up to 216 Si atoms. A number of configurations with three or more self-interstitials are found, and the lowest-energy ones are discussed. The binding energies of Inrelative to In−1+I show that the first ‘magic number’ (particularly stable aggregate) is I3. The potential energy surfaces for aggregates of three or more I's have several local minima, leading to a range of metastable configurations.