Crystal Structure and Chemical Bonding of Mg3Ru2

Mg3Ru2 was prepared by a reaction between the elements in the ideal ratio in a sealed tantalum ampule. Its β-manganese type crystal structure was refined on the basis of the single-crystal data: space group P4132, a = 693.52(6) pm, wR2 = 0.024, 168 F2 values, and 10 parameters. The magnesium (CN = 14) and ruthenium (CN = 12) atoms are completely ordered on the 12d and 8c sites of the crystal structure of β-manganese. Both environments can be considered as Frank−Kasper related polyhedra. A periodic nodal surface P4132⟨(110)π1⟩P4132 separates the magnesium and ruthenium positions in two different labyrinths, suggesting different chemical interactions within different parts of the structural motif. Analysis of the chemical bonding with the electron localizability indicator (ELI-D) reveals covalently interacting three-bonded ruthenium atoms, forming a 3D network. The network interacts with the magnesium substructure by multicenter bonds.