A nonorthogonal tight-binding model for hydrocarbon molecules and nanostructures

In spirit of extended- Huckel approximations, we have developed a nonorthogonal tight-binding total energy model for hydrocarbons with only a few adjustable parameters. Our model reproduces the geometry structures, binding energies, on-site charge transfer and vibrational frequencies of a variety of hydrocarbon molecules reasonably well. Comparative calculations on carbon fullerenes and nanotubes using tight-binding model and density functional theory demonstrate the potential of applying this model to large scale simulations of carbon nanostructures.