The intermetallic germanides CaNiGe and MgCoGe have been synthesized from the elements in sealed tantalum tubes in a high‐frequency furnace. The compounds were investigated by X‐ray diffractions both on powders and single crystals: CeFeSi structure type, P4/nmm, a = 4.19341(3), c = 6.6264(1) Å, wR2 = 0.030, 124 F2 values, 10 variable parameters for CaNiGe and a = 3.8960(4), b = 6.1929(11) Å, wR2 = 0.048, 104 F2 values, 10 variable parameters for MgCoGe. In CaNiGe and MgCoGe the transition metal and germanium atoms build [TGe] layers (T = Ni, Co), which are separated by the calcium and magnesium atoms, respectively. The crystal structures of CaNiGe and MgCoGe as well as chemical bonding in CaNiGe and CaNi2Ge2 are discussed in terms of LMTO bond structure calculation and analysis using the Electron Localization Function (ELF). The Ge–Ge bond formation in polyanionic $^{3}_{\infty}\rm [NiGe]^{-}$ network of CaNi2Ge2 can formally be regarded as oxidative coupling product of $^{2}_{\infty}\rm [NiGe]^{2-}$ layers of CaNiGe.

No abstract

In 6 and Pr7Ni5±xGe3±xIn6. -Ce7Ni4.73Ge3.27In6 and Pr7Ni4.96Ge3.04In6 are prepared by arc-melting of the elements and characterized by single crystal XRD and magnetic measurements. The compounds crystallize in the space group P6/m with Z = 1. The new structure type can be derived from the AlB2-type structure by substitution of the Al and B atoms by CeM 12 (M: Ge/Ni) hexagonal prisms an tricapped trigonal prismatic NiIn 6 Ce 3 polyhedra. Polycrystallin Ce7Ni5Ge3In6 shows Curie-Weiss like paramagnetic behavior down t 1.71 K. -(CHUMALO, N.; NYCHYPORUK, G. P.; PAVLYUK, V. V.; POETTGEN*, R.; KACZOROWSKI, D.; ZAREMBA, V. I.; J. Solid State Chem. 183 (2010) 12, 2963-2967, http://dx.