Computational method for the intrasite matrix elements of the Hamiltonian for tight-binding molecular dynamics calculations

A method has been developed for computing the intrasite matrix elements of the Hamiltonian for tight-binding molecular dynamics (TBMD). In conventional TBMD, intrasite matrix elements are usually replaced by the matrix elements of the isolated atom or approximated by an empirical equation. In contrast to this, this method calculates them directly using a Slater-Koster-like scheme, and is applicable to any atomic configuration. The amount of computation time required for this method is not significantly higher than the conventional method. A test calculation for the Hamiltonian of silicon indicates that this method is as accurate as the exact calculation using numerical integral. TBMD is expected to be more accurate using this method.