CsLiGe, One Compound with Two Complementary Structural Descriptions: Isolated [Ge] Tetrahedral Clusters Coordinated by Li and Cs Cations or One-Dimensional [LiGe] Polyanions Packed within a Matrix of Cs Cations?

Reported are the synthesis and structural characterization of CsLiGe, the first structurally characterized lithium-containing cesium germanide. Single-crystal X-ray diffraction data indicate that CsLiGe crystallizes in an orthorhombic crystal system with the space group (no. 63, Person symbol 32) with unit cell parameters = 6.

Adaptation of the BaAl Type to Small Cations: The Case of NaGa.

Single-phase NaGa samples were prepared by annealing stoichiometric element mixtures at 200 °C, 300 °C, and 450 °C in closed tantalum ampoules. No compositional homogeneity range was detected. While single crystals annealed at 200 °C feature a fully ordered crystal structure, a crystal annealed at 300 °C reveals a defect with mutual exchange of Na atoms and Ga dumbbells.

Deciphering the Polymorphism of CaSi: The Influence of Heat and Composition.

The Zintl phase CaSi is a layered compound with stacking variants known as 1P, 3R, and 6R. We extend the series by the 21R polytype formed by rapid cooling of the melt. The crystal structure of 21R-CaSi (space group 3̅) was derived from HRTEM images, and the atomic positions were optimized by using the FPLO code ( = 3.