Etude structurale de combinaisons sulfurées et séleniées du molybdène. III. Structure cristalline de NiMo3S4

The crystals of NiMo₃S₄, are rhombohedral, space group $\text{R}\text{3}$, with two formula units in a cell: a = 6.462 Å, α = 94.68°.The structure was solved by the heavy atom method and refined by a full-matrix least-squares program to R = 0.077 for 1026 independent reflexions. The arrangement of Mo and S atoms in the cell is approximately the same as described before for Mo and Se atoms in Mo₃Se₄ and Ni_0.33Mo₃Se₄; the Ni atoms are situated along the channel based on x = 0, y = 0. However, in these two compounds the lattice of Se presents a covalent character when the lattice of S in NiMo₃S₄ has an essentially ionic character.