Computational materials synthesis .1. A tight-binding scheme for hydrocarbons

A simple quantum mechanical model is presented for hydrocarbons. It is a modified version of the model of Davidson and Pickett [Phys. Rev. B 49, 11 253 (1994)]. Self-consistency is introduced through the imposition of local charge neutrality, which is appropriate for hydrogen and carbon based systems due to the small amount of charge transfer that takes place. Further, some parameters have been refitted to give the correct binding energies as well as forces. The model is found to give excellent agreement with experiment and other calculations for hydrocarbon molecules and the hydrogenated surface of diamond, demonstrating its transferability.