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 I(n) relative to I(n-1) + I show that the first 'magic number' (particularly stable aggregate) is I(3). The potential energy surfaces for aggregates of three or more I's have several local minima, leading to a range of metastable configurations. (C) 1999 Elsevier Science B.V. All rights reserved.