Photoemission spectra and band structures ofd-band metals. I. Practical aspects of fcc interpolation schemes

A variant is described of the combined interpolation scheme for the band structures of the face-centered-cubic $d$-band metals, devised originally by Hodges et al. and by Mueller. Since it is intended to use the scheme in the interpretation of photoemission experiments, where optical transitions can occur to states well above the Fermi level, special attention has been paid to obtaining a good reproduction of the unoccupied bands. It is found that this is achieved by a suitable choice for the parameters, $V_{111}$ and $V_{200}$, representing the purely local part of the pseudopotential and the coefficient $S$ of a nonlocal contribution to the pseudopotential arising from explicit orthogonalization to the $d$ states. The band structures of Ni, Cu, Rh, Pd, Ag, Ir, Pt, and Au have been calculated by a nonrelativistic augmented-plane-wave method, and the parameters of the scheme have been fitted to the results by a nonlinear least-squares method. These parameters are to be used in a subsequent paper as the starting point of an interpretation of photoelectron energy spectra.