Materials Data on Mg4(MoO4)3 by Materials Project
Mg4(MoO4)3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent MoO4 tetrahedra and faces with two equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.03–2.12 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share a cornercorner with one MgO6 octahedra, a cornercorner with one MgO6 pentagonal pyramid, corners with three equivalent MoO4 tetrahedra, and edges with two equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of Mg–O bond distances ranging from 2.03–2.24 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing MgO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 65°. There are a spread of Mg–O bond distances ranging from 2.12–2.17 Å. There are two inequivalent Mo+5.33+ sites. In the first Mo+5.33+ site, Mo+5.33+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Mo–O bond distances ranging from 1.84–2.52 Å. In the second Mo+5.33+ site, Mo+5.33+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 27–63°. There is three shorter (1.79 Å) and one longer (1.83 Å) Mo–O bond length. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one Mo+5.33+ atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to two Mg2+ and one Mo+5.33+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one Mo+5.33+ atom. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg2+ and two equivalent Mo+5.33+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Mg2+ and one Mo+5.33+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Mg2+ and one Mo+5.33+ atom. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Mg2+ and one Mo+5.33+ atom.