Acta Crystallographica Section B

Structural Science

Volume 56, Part 3 (June 2000)

research papers

Acta Cryst. (2000). B56, 431-437 [ doi:10.1107/S0108768100000550 ]

Redetermination of the crystal structures of the `Arppe compound' Bi₂₄O₃₁Cl₁₀ and the isomorphous Bi₂₄O₃₁Br₁₀

U. Eggenweiler, E. Keller and V. Krämer

Abstract: The crystal structures of Bi₂₄O₃₁X₁₀ (X = Cl, Br; 24-bismuth 31-oxide decachloride/-bromide) have been redetermined. The structure models obtained resemble the model described in the literature about 60 years ago, but differ from it in some details of the O substructure and in the fact that the structure for X = Cl is a twofold superstructure of the literature model. A fictional mechanism is given by which the formerly described incorrect O substructure is transferred into the correct one.

Keywords: Arppe compound; Isomorphous; Superstructures.