Electronic structure and optical spectra of LuInCu4 and YbMCu4 (M=Cu, Ag, Au, Pd, and In)

Optical reflectivity measurements over a wide spectral range and at different temperatures together with self-consistent electronic band structure calculations have been used to investigate the electronic structure of the LuInCu4 and YbMCu4 (M = Cu,Ag,Au,Pd,In) compounds. The electronic structure of the compounds is investigated theoretically using an energy-band approach in combination with the linear-response formalism. The energy-hand structure is obtained within the local-spin-density approximation (LSDA) and within its extension that explicitly takes into account the on-site 4f Coulomb interaction Lr (LSDA + U). A remarkable agreement between theory and experiment has been found.