Tight-binding simulation of liquid and amorphous Si at zero pressure

Using a parametrization of the tight-binding Hamiltonian which includes s, p, and d orbitals, we simulate liquid Si; it has the experimental density at zero pressure. Short and intermediate range order, atom dynamics and electronic density of states are in good agreement with ab initio results. Discrepancies are seen, however, in a slightly too small coordination number, accompanied by a lack of bond angles around 60 degrees, and a somewhat too large contribution of the high-frequency phonon branch to the power spectrum. When quenching this liquid alone the zero pressure isobar, we obtain amorphous silicon: its properties agree favorably with ab initio data. (C) 1999 Elsevier Science B.V. All rights reserved.