Electronic structure of copper pnictides: Influence of different cations and pnictogens

We present calculated electronic structures and x-ray emission and absorption spectroscopy measurements of five copper pnictides. The x-ray emission and absorption spectra, which probe the occupied and unoccupied states, respectively, provide an empirical justification of the calculated electronic structure. We therefore verify the prediction that the copper 3d states are fully occupied and buried deep in the valence band, and the Fermi surface of these materials is characterized by s,p states. We show that generally the calculated electronic structure is in excellent agreement with our measurements. We finally examine the Fermi surfaces of these pnictides, and suggest that copper antimonides may exhibit efficient Fermi surface nesting similar to iron pnictides.