Non-muffin-tin effects in the4dtransition metals Rb, Nb, and Pd

While the effects of corrections to the muffin-tin model of the crystal potential have been investigated fairly thoroughly for various insulators and semiconductors, relatively few complete calculations have been done for transition metals. The Hartree-Fock-Slater muffin-tin approximate potential is usually adequate for characterization of the general properties of free-electron metals. In the transition-metals series, however, where the Fermi energy typically lies in a partially filled $d$ band, it is recognized that small nonuniform energy shifts can appreciably alter the properties dependent upon the detailed topology of the Fermi surface. Here, we report the application of the recently proposed combined Korringa-Kohn-Rostoker discrete variational method for several crystals representative of the $4d$ transition-metal series. Results are analyzed directly in terms of the Bloch wave functions and various trends and general features of non-muffin-tin effects in the transition metals are determined.