A semi-empirical potential for the statics and dynamics of covalent carbon systems

The statics and dynamics of different carbon crystals and compounds were studied using a semi-empirical potential, of the form proposed by Tersoff with the addition of a torsion-like term, proposed to overcome the inadequacy of the original potential to describe the dynamics of these systems. The potential parameters were refined by fitting the observed properties of graphite and diamond; the r.m.s. deviations for the vibrational frequencies were reduced by a factor of about 3. The potential is applied to systems not included in the fit, yielding excellent agreement with experimental data on Lonsdaleite and fullerenes.