AbstractA new quantum-mechanical method capable of determining atomic configurations of extended defects has been developed. The Hamiltonian is constructed using the first-principles tight-binding linear muffin-tin orbital method in the atomic-sphere approximation. A semiempirical correction is employed to describe the effect of electrons in the interstitial region and the repulsive part of the total energy is described by a pair potential. The forces on atoms are calculated by differentiating the corresponding energy terms with respect to atomic positions. The equilibriun configuration is then found by minimizing the total energy. In this approach, the electronic and chemical aspects of defect structures can be accounted for more adequately than when using central-force pair or many-body potentials. In particular, the angular dependence of interatomic forces, which is important in transition metals with unfilled d-bands, is described correctly within the present quantum-mechanical treatment.
Tight-binding parameters from the full-potential linear muffin-tin orbital method: A feasibility study on NiAl