A nonorthogonal tight-binding total energy model for molecular simulations

Abstract

A nonorthogonal tight-binding (TB) total energy model for molecular simulations has been developed in spirit of extended-Hückel theory. The semiempirical potential parameters for H, C, O elements are fitted from density functional theory (DFT) calculations. The test calculations on small inorganic molecules, hydrocarbons, fullerenes, and large organic molecules show its reliability and transferability. In particular, the atomization energies and the gaps between highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO–LUMO gaps) from TB model compare well with DFT results for a variety of molecules. Thus, our TB model can be used in the large scale simulation of molecules and carbon-based materials.