INTERATOMIC POTENTIAL FOR SILICON CLUSTERS, CRYSTALS, AND SURFACES

We have developed an interatomic potential suitable for the modeling of silicon in a wide range of bonding environments. The potential is of the general form developed by Tersoff, with the interaction between a pair of atoms being dependent on the environment of the pair. The atom-atom potential-energy function is expressed as a sum of and -bonding terms, each independently influenced by the environment. The functional form of the potential and the parameters in the potential were chosen to fit a variety of data on silicon, including the structure and energy of small clusters of 210 atoms, the crystal structures, the elastic constants of the diamond-lattice phase, and some surface properties. We present the results of using this potential to model small clusters (210 atoms), crystal phases, point defects in the diamond lattice, the 2×1 reconstructions of the Si(100) and Si(111) surfaces, and the 7×7 reconstruction of Si(111). Our present potential is compared in detail to other potentials that have been developed to model the properties of silicon. © 1990 The American Physical Society.