 In general because of the metallic lattice, these types of materials, for example Cu6Sn5, Mn2Sb, lower voltages and higher capacities have been found when compared to their oxide counterparts.Cu6Sn5 is an intermetallic alloy with a defect NiAs type structure.In NiAs type nomenclature it would have the stoichiometry Cu0.2CuSn, with 0.2 Cu atoms occupying a usually unoccupied crystallographic position in the lattice.