Korrektur zur Kristallstruktur von „Cs4PbO3”︁ und die Strukturverwandtschaft zwischen den Modifikationen von Cs4PbO4

Correction of the Crystal Structure of “Cs₄PbO₃” and the Structural Relationship between the Modifications of Cs₄PbO₄ The compound that has been described as Cs₄PbO₃ really is Cs₄PbO₄. It does not crystallize in the space group P2₁, as assumed, but in P2₁/c. The observed fictitiuous violation of the extinction law for the c glide plane is due to twinning. The structure was refined using the original data as well as new data from an untwinned crystal. The denomination β-Cs₄PbO₄ is used to distinguish this structure from another known modification (α-Cs₄PbO₄). Both structures, α-Cs₄PbO₄ and β-Cs₄PbO₄, can be derived from the sphere packing of γ-plutonium when certain voids in its packing are occupied with oxygen atoms.     

Darstellung und Strukturdaten von „Delafossiten”︁ CuMO2 (M = Al,Ga, Sc,Y)

Synthesis and Structural Data of “Delafossites” CuMO₂ (M = Al, Ga, Sc, Y) By solid state reaction of their binary components 2H-CuScO₂, R-CuGaO₂, and R-CuYO₂ were synthesized for the first time. Their crystal structures were determined, and those of R-CuAlO₂ and 2H-CuAlO₂ refined. Characteristic structural features (lattice constants and interatomic distances) are discussed with respect to possible Cu⁺? Cu⁺ interactions.