CALCULATION OF WANNIER FUNCTIONS FOR FCC TRANSITION-METALS BY FOURIERTRANSFORMATION OF BLOCH FUNCTIONS

A method is described for the calculation of generalized symmetry-adap ted Wannier functions by Fourier transformation of Bloch functions obt ained by standard first-principles techniques. An additional unitary t ransformation derived from a Slater-Koster-model Hamiltonian is introd uced in order to deal with the nonanalytical behavior of the Bloch fun ctions. The parameters of the Hamiltonian, which are the energy matrix elements of the Wannier functions, reproduce the first-principles ban d structure with high accuracy. It is considered in detail how problem s caused by degeneracies have to be treated by an analysis of transfor mation properties at symmetry points. An application to fcc transition metals yields highly localized functions of d symmetry, an s function whose localization depends on the strength of relativistic effects, a nd less localized p functions.