Efficient ab initio tight-binding-like method for electronic structure calculations

A reliable and highly efficient ab initio tight-binding-like electronic structure calculation method is developed. The method starts from a similar approach outlined by Horsfield [Phys. Rev. B 56, 6594 (1997)], but in this work, the integral evaluations for the exchange-correlation matrix elements are achieved with reasonable accuracy by higher-order many-center expansions. All the integrals are obtained by the use of look-up tables and the efficiency of the calculation is further improved by optimizing the way to choose the integrals in the look-up tables. Calculations on molecular properties (such as equilibrium geometries, dipole moments, and the reaction energies for hydrogenation reactions for a series of molecules containing H, C, N, and O atoms) show that the method thus developed can be used as a general tool for the electronic structure calculations.