Nonconventional tight-binding method for the calculation of the total energy and spectroscopic energies of atomic clusters: Transferable parameters for silicon

The principal differences between conventional tight-binding methods and a nonconventional tight-binding method proposed earlier by one of the authors [Z. M. Khakimov, Comput. Mater. Sci. 3, 95 (1994)] are highlighted here. The latter has been optimized for simulation of the structure, cohesive energies, ionization potentials, and electronic affinities of silicon clusters. A single tight-binding approximation has been used to predict all of the above properties with accuracy comparable to state-of-the-art ab initio methods. This demonstrates the potential of tight-binding methods as a quantitative, predictive tool, provided they are based on an accurate total energy functional and exploit properly the individual properties of chemical elements, accounting for both intra- and interatomic charge redistributions.