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 su percells 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 In-1 + I show that the f irst 'magic number' (particularly stable aggregate) is I-3. The potential e nergy surfaces for aggregates of three or more I's have several local minim a, leading to a range of metastable configurations. (C) 1999 Elsevier Scien ce B.V. All rights reserved.