@article{discovery1449266, journal = {Acta Crystallographica Section E: Structure Reports Online}, title = {Crystal structure of magnesium selenate heptahydrate, MgSeO7HO, from neutron time-of-flight data}, pages = {134 -- 137}, note = {This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.}, volume = {70}, number = {9}, year = {2014}, month = {August}, url = {http://dx.doi.org/10.1107/S1600536814018698}, author = {Fortes, AD and Gutmann, MJ}, abstract = {MgSeO7HO is isostructural with the analogous sulfate, MgSO7HO, consisting of isolated [Mg(HO)]octahedra and [SeO]tetrahedra, linked by O - O hydrogen bonds, with a single interstitial lattice water molecule. As in the sulfate, the [Mg(HO)]coordination octahedron is elongated along one axis due to the tetrahedral coordination of the two apical water molecules; these have Mg - O distances of {$\sim$}2.10 {\AA}, whereas the remaining four trigonally coordinated water molecules have Mg - O distances of {$\sim$}2.05 {\AA}. The mean Se - O bond length is 1.641 {\AA} and is in excellent agreement with other selenates. The unit-cell volume of MgSeO7HO at 10 K is 4.1\% larger than that of the sulfate at 2 K, although this is not uniform; the greater part of the expansion is along the a axis of the crystal.} }