TRANSFERABLE TIGHT-BINDING PARAMETERS - AN APPLICATION TO NI AND NI-AL ALLOYS

The first-principles transformation of the linear muffin-tin orbitals (LMTO) into a tight-binding (TB) basis provides a reliable and very efficient method of obtaining the so-called Slater-Koster (SK) parameters, which can be used to gain insight into the electronic structure of complex systems, where conventional ab initio methods become too computer intensive. In this work we study the usefulness and the reliability of the SK parameters obtained from the TB-LMTO method, by examining their (i) transferability with changes in structural and chemical environments and (ii) applicability over a wide range of interatomic separations through explicit charge self-consistent LMTO calculations using Ni and Ni-Al systems as examples. We further test these parameters by comparing the densities of states and the effective pair interactions of Ni-Al system with the results of the more accurate Korringa-Kohn-Rostoker-coherent potential approximation method. We also compare our results with the SK parameters obtained empirically.