Orientational disorder of [Mg(H2O)6] octahedra in the novel magnesium selenite hydrate Mg(SeO3).7.5H2O.
The crystal structure of magnesium selenite 7.5-hydrate, Mg(SeO3).7.5H2O (space group P6(3)/mmc), is characterized by two crystallographically distinct [Mg(H2O)6]2+ octahedra, one of which is disordered over two different orientations. The selenite groups and water molecules (with partially disordered H atoms) bridge the octahedra via hydrogen bonds. All the atoms are located on special positions, except for one water molecule.
Fleck
Michel
M
Universität Wien-Geozentrum, Institut für Mineralogie und Kristallographie, Althanstrasse 14, A-1090 Wien, Austria. michel.fleck@univie.ac.at