Crystal structure of R₃Mg_0.5DSe₇ (R = Ce, Pr; D = Si, Ge)

Chem. Met. Alloys 8 (2015) 16-21

https://doi.org/10.30970/cma8.0298

Oksana STROK, Marek DASZKIEWICZ, Lubomir GULAY

The crystal structures of four quaternary R₃Mg_0.5DSe₇ compounds (structure type La₃Mn_0.5SiS₇, space group P6₃, Pearson code hP23, a = 10.669(1) Å, c = 6.0611(8) Å, R1 = 0.0252 for Ce₃Mg_0.5SiSe₇; a = 10.531(1) Å, c = 6.0420(1) Å, R1 = 0.0275 for Pr₃Mg_0.5SiSe₇; a = 10.6579(7) Å, c = 6.0430(7) Å, R1 = 0.0249 for Ce₃Mg_0.5GeSe₇; a = 10.615(1) Å, c = 6.0329(7) Å, R1 = 0.0406 for Pr₃Mg_0.5GeSe₇) were determined by means of X-ray single-crystal diffraction. The R atoms occupy trigonal prisms capped by two additional atoms. The Mg atoms are located in octahedra and the D atoms in tetrahedra.

Packing of [CeSe1₁Se2₄Se3₃] bi-capped trigonal prisms, [МgSe2₆] octahedra and [SiSe1₁Se3₃] tetrahedra in the structure of Ce₃Mg_0.5SiSe₇.

Keywords

Rare-earth compounds / Chalcogenides / Crystal structure / X-ray single-crystal diffraction