Phase Shift Parametrization: Band Structure of Silver

Abstract

We discuss a band parametrization scheme (within the KKR framework) specifying the phase shifts n₀, n₁, and n₂ as functions of energy. Such an approach is particularly useful for the noble and transition metals where both d-band and free-electron-like effects are important. The n_ℓ(E) for a family of elements are expected to have characteristic energy dependences, with each n_ℓ(E) being specified over a substantial energy range by a few parameters. First, we show the existence of such characteristic behavior for the noble metals. We then use our phase shift parametrization scheme in a semi-empirical way to find the band structure of Ag. To do this, we use a first principles calculation as a guide, and adjust the parameters specifying the n_ℓ(E) to fit available Fermi surface, optical and photoemission data.