Atomistic Computer Modelling in Advanced Materials R & D

Abstract

One way to model the behaviour of advanced materials is to use ab initio total energy calculations. Because these are normally limited in practice to 20–100 atoms either a small supercell or a small fragment of the solid is used. We have chosen a small fragment of silicon with a hydrogenated surface (comprising 26 atoms) to evaluate the formation energy of an ideal vacancy and the activation energy for concerted exchange of atoms. The preliminary results reported here are in reasonable agreement with solid state calculations.

Key Words:

• Advanced Materials
• defect energies
• Silicon