The monogermanide LuGe is obtained via high‐pressure high‐temperature synthesis (5–15 GPa, 1023–1423 K). The crystal structure is solved from single‐crystal X‐ray diffraction data (structure type FeB, space groupPnma,a=7.660(2) Å,b=3.875(1) Å, andc=5.715(2) Å, R_F=0.036 for 206 symmetry independent reflections). The analysis of chemical bonding applying quantum‐chemical techniques in position space was performed. It revealed—beside the expected 2c‐Ge‐Ge bonds in the germanium polyanion—rather unexpected four‐atomic bonds between lutetium atoms indicating the formation of a polycation by the excess electrons in the system Lu³⁺(2b)Ge²⁻×1 e⁻. Despite the reduced VEC of 3.5, lutetium monogermanide is following the extended 8‐N rule with the trend to form lutetium‐lutetium bonds utilizing the electrons left after satisfying the bonding needs in the anionic Ge‐Ge zigzag chain.

The new intermetallic compound Eu₂Pd₂Sn has been investigated. A single crystal was selected from the alloy and was analyzed by single-crystal X-ray diffraction, revealing that this compound possesses the noncentrosymmetric Ca₂Pd₂Ge structure type being, so far, the only rare-earth-based representative. Bonding analysis, performed on the basis of DOS and (I)COHP, reveals the presence of strong covalent Sn–Pd bonds in addition to linear and equidistant Pd–Pd chains. The incomplete ionization of Eu leads to its participation in weaker covalent interactions. The magnetic effective moment, extracted from the magnetic susceptibility χ(T) is μ_eff = 7.87 μ_B, close to the free ion Eu²⁺ value (μ_eff = 7.94 μ_B). The maximum of χ(T) at T_N ∼ 13 K indicates an antiferromagnetic behavior below this temperature. A coincident sharp anomaly in the specific heat C_P(T) emerges from a broad anomaly centered at around 10 K. From the reduced jump in the heat capacity at T_N a scenario of a transition to an incommensurate antiferromagnetic phase below T_N followed by a commensurate configuration below 10 K is suggested.

The R ₂ PdGe ₆ series (R = rare earth metal) was analyzed from structural and theoretical point of view.

The chemical bonding, structural and magnetic properties of EuPdSn ₂ have been investigated by DFT, synchrotron X-ray and neutron powder diffraction and ¹⁵¹ Eu Mössbauer spectroscopy.