Fitting the Stillinger–Weber potential to amorphous silicon

Modifications are proposed to the Stillinger–Weber (SW) potential, an empirical interaction potential for silicon. The modifications are specifically intended to improve the description of the amorphous phase and are obtained by a direct fit to the amorphous structure. The potential is adjusted to reproduce the location of the transverse optic (TO) and transverse acoustic (TA) peaks of the vibrational density of states (VDOS), properties insensitive to the details of experimental preparation. These modifications also lead to excellent agreement with structural properties. Comparison with other empirical potentials shows that amorphous silicon configurations generated with the modified potential have overall better vibrational and structural properties.