Ground state and electronic structures of the series Li2Cu1−xSxSb with (x = 0, 1/8, 2/8, 3/8, 4/8, 5/8, 6/8, 7/8, 1)

Li2CuSb is considered as multifunctional material, electrode for high capacity of rechargeable batteries and novel material for second harmonic generation. First principle electronic structure calculations of series Li2Cu1−xSxSb (with x = 0, 1/8, 2/8, 3/8, 4/8, 5/8, 6/8, 7/8, 1) has been done. New optimized distribution has been introduced for atoms among the allowed positions of the Heusler structure Li2CuSb. The primary compound Li2CuSb is a Heusler compound based on one 3d transition metal. The injection of S into Li2CuSb, instead of Cu, introduces a new aspects about the important role of 3d in the electrical properties of the compound. Theoretical investigation of the effect of atomic positions on the properties of the series is included. These calculations show that moving Li atom from the surface of the unit cell into the inside improves the compound applications in the high capacity of rechargeable batteries. The present calculations are in agreement with the previous theoretical and experimental publications in the increase of capacity [1,2]. Band structure and DOS indicate an increase in the density of states at Fermi level with more dispersion for the occupied states of Li2Cu7S1Sb and Li2Cu1S7Sb. As a result, the electronic specific heat coefficient and the conductivity increases.