Electronic structure of copper free superconductors and related compounds

We extract the common features of the electronic structure for the normal state of the pure compounds, obtained from ab-initio local density approximation (LDA) bands structure calculation with the APW method, and the characteristics of the alloys calculated with a tight-binding (TB) Coherent Potential Approximation (CPA) method. Endly, we show that a simple model including only the s orbitals of the metal on the Bi-Site and the pσ-orbitals of oxygen leads to the perfect nesting of the Fermi surface of BaBiO3 and a possible attractive Coulomb interaction on the Bi-atom. (orig.)