Title: ELECTRONIC STRUCTURE OF MIXED VALENT SYSTEMS
Authors: V.N.Antonov, A.P.Shpak (Institute of Metal Physics of the National Academy of Sciences of Ukraine, 36 Vernadsky str., 03142 Kiev), A.N.Yaresko (Max Planck Institute for Physics of Complex Systems, D-01187 Dresden, Germany)

The electronic structure of Tm and Sm monochalcogenides, SmB6 and Yb4As3 is theoretically investigated from the first principles, using the fully relativistic Dirac LMTO band structure method. The electronic structure is obtained using the local spin-density approximation (LSDA), as well as the so-called LSDA+U approach. While the standard LSDA approach is incapable of correctly describing the electronic structure of such materials due to the strong on-site Coulomb repulsion, the LSDA+U approach is remarkably accurate in providing a detailed agreement with experiment for a number of properties.

Key words: strongly correlated systems, optics, band structure
PACS: 71.28.+d, 71.25.Pi, 75.30.Mb