Crystal structure of new intermetallic compound Mg3Co2Ga7

The Mg3Co2Ga7 compound was prepared by a reaction of the elemental components in arc furnace and subsequent annealing at 670 K. Its crystal structure was solved and refined from X-ray single crystal data. Mg3Co2Ga7 is a new structure type: monoclinic space group C2/c, a = 9.0873(9) Å, b = 9.4598(9) Å, c = 9.4361(9) Å, β = 93.605(8)°, V = 809.5(1) Å3. The coordination around magnesium atoms consist of 13 and 14 atoms. The icosahedron and tetragonal antiprismatic coordination for the gallium and cobalt atoms was obtained. The structure belongs to class 9, according to the Krypyakevich classification scheme.