Synthesis, characterization, structural and theoretical analysis of a new rare-earth boride carbide: Lu3BC3

Lu3BC3 is prepared by are-melting of the elements. The silver colored compo und crystallizes in the space group Cmcm (Z = 4, a = 4.9788(3) Angstrom, b = 5.0109(3) Angstrom, c = 15.669(1) Angstrom). The crystal structure contai ns discrete carbon atoms and CBC units in octahedra and bicapped cubes of m etal atoms, respectively. The structural analysis is consistent with the gr oup oxidation states (Lu3+)(3)(C4-)(CBC5-). Extended Huckel and LAPW calcul ations have been performed. Although a semiconducting behavior could be ant icipated, the valence band and the conduction band are touching according t o LAPW calculations in agreement with the observed metallic conductivity of the compound.