Water channel structure of bassanite at high air humidity: crystal structure of CaSO₄·0.625H₂O. Corrigendum

Abstract

The correspondence author in the paper by Schmidt et al. [(2011), Acta Cryst. B67, 467–475] is corrected.

Monoclinic Form of the Rhabdophane Compounds: REEPO4·0.667H2O

“…We can cite, as an example, the case of the CaSO 4 · n H 2 O compounds for which controversial discussions occurred about the true crystal structure (hexagonal or not) and the role of the water amount inside the channels. It was finally shown that CaSO 4 ·0.5H 2 O − crystallizes in a C 2 space group, while the CaSO 4 ·0.625H 2 O , crystallizes in a P 3 2 21 space group by doubling the original hexagonal unit cell parameters. However, both structures derivate from the original hexagonal model, , but differ markedly in terms of the water molecules arrangement.…”

“…However, from the synthesis point of a view, the control of the amount of the water molecules inside the channels seems to be difficult so far. However, it could be possible during the dehydration and/or the rehydration steps or also by varying the relative humidity as shown by Schmidt et al in the case of the CaSO 4 ·0.5H 2 O. , The stabilization of the rhabdophane compounds by precipitation in aqueous solution represents a reliable procedure leading to pure phases with a variety of textural and microstructural properties. Moreover, it is in agreement with the different observations found in nature. ,,, …”