Tight‐Binding Electronic Theory for Lattice Defects in Transition Metals. Correlation Effects

Abstract

A tight-binding type electronic theory is used to calculate the atomic relaxation (a&), formation and binding energies (Ef, and &,in) of vacancy-type lattice defects in transition metals. The shortrange repulsive energies between atomic sites i and j are simulated by the Born-Mayer potential.An electronic correlation contribution is taken into account using a second-order perturbation theory within the Hubbard model. It is shown that correlation effects play a significant role in determining the physical properties of the lattice defects (aR,, Ef,, and &,in) in transition metals. This tendency is observed for the lattice defects on the surface as well.Eine elektronische "tight-binding"-Theorie wird benutzt, urn die atomare Relaxation (a&), die Tendenz wird auch fur die Gitterdefekte a n der Oberflache beobachtet.