Materials Data on MgH2(SeO4)2 by Materials Project
MgH2(SeO4)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent SeO4 tetrahedra. There are four shorter (2.09 Å) and two longer (2.15 Å) Mg–O bond lengths. H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.64 Å) H–O bond length. Se6+ is bonded to four O2- atoms to form SeO4 tetrahedra that share corners with three equivalent MgO6 octahedra. The corner-sharing octahedra tilt angles range from 43–47°. There are a spread of Se–O bond distances ranging from 1.64–1.75 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one H1+ and one Se6+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mg2+ and one Se6+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mg2+ and one Se6+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one H1+, and one Se6+ atom.