Materials Data on Mg2GeO4 by Materials Project

Mg2GeO4 is Spinel-like structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with four equivalent MgO6 octahedra, corners with two equivalent GeO4 tetrahedra, edges with four MgO6 octahedra, and edges with two equivalent GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–59°. There are a spread of Mg–O bond distances ranging from 2.09–2.17 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with eight MgO6 octahedra, corners with four equivalent GeO4 tetrahedra, edges with two equivalent MgO6 octahedra, and an edgeedge with one GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–59°. There are a spread of Mg–O bond distances ranging from 2.08–2.27 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with six MgO6 octahedra and edges with three MgO6 octahedra. The corner-sharing octahedra tilt angles range from 59–63°. There are a spread of Ge–O bond distances ranging from 1.75–1.81 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one Ge4+ atom. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one Ge4+ atom. In the third O2- site, O2- is bonded to three Mg2+ and one Ge4+ atom to form distorted corner-sharing OMg3Ge tetrahedra.