LiBC3: a new borocarbide based on graphene and heterographene networks.

Li-B-C alloys have attracted much interest because of their potential use in lithium-ion batteries and superconducting materials. The formation of the new compound LiBC3 [lithium boron tricarbide; own structure type, space group P-6m2, a = 2.5408 (3) Å and c = 7.5989 (9) Å] has been revealed and belongs to the graphite-like structure family. The crystal structure of LiBC3 presents hexagonal graphene carbon networks, lithium layers and heterographene B/C networks, alternating sequentially along the c axis. According to electronic structure calculations using the tight-binding linear muffin-tin orbital-atomic spheres approximations (TB-LMTO-ASA) method, strong covalent B-C and C-C interactions are established. The coordination polyhedra for the B and C atoms are trigonal prisms and for the Li atoms are hexagonal prisms.