Energetic, vibrational, and electronic properties of silicon using a nonorthogonal tight-binding model

We present calculations of energetic, electronic, and vibrational propertie s of silicon using a nonorthogonal tight-binding (TB) model derived to fit accurately first-principles calculations. Although it was fit only to a few high-symmetry bulk structures, the model can be successfully used to compu te the energies and structures of a wide range of configurations. These inc lude phonon frequencies at high-symmetry points, bulk point defects such as vacancies and interstitials, and surface reconstructions. The TS parametri zation reproduces experimental measurements and ab initio calculations well , indicating that it describes faithfully the underlying physics of bonding in silicon. We apply this model to the study of finite temperature vibrati onal properties of crystalline silicon and the electronic structure of amor phous systems that are too large to be practically simulated with ab initio methods.