Ce3Mg0.5GeS7 from single-crystal data

✍ Scribed by Gulay, L. D. ;Daszkiewicz, M. ;Huch, M. R. ;Pietraszko, A.

• Publisher: International Union of Crystallography
• Year: 2007
• Tongue: English
• Weight: 551 KB
• Volume: 63
• Category: Article
• ISSN: 1600-5368
• DOI: 10.1107/s1600536807048593

✦ Synopsis

Single crystals of tricerium hemimagnesium germanium heptasulfide were obtained by sintering a Ce~2~S~3~–MgS–GeS~2~ mixture. The compound crystallizes in the space group __P__6~3~ and is isotypic with other Ln~3~
T
~0.5~
__X__S~7~ phases (Ln = lanthanide, T = divalent transition metal, and X = Si or Ge). The slightly distorted trigonal [MgS~6~] antiprism has 3 symmetry, with the Mg position half-occupied. The latter position correlates well with the disordered Ag2 positions in the Ln~3~Ag~1−δ~SnS~7~ (Ln = La, Ce; δ = 0.18–0.19) and Ln~3~Ag~1−δ~SiS~7~ (Ln = La–Nd, Sm; δ = 0.10–0.23) structures. The present single-crystal study confirms the previous refinement from powder data, but with all displacement parameters refined anisotropically.