Materials Data on MgGeO3 by Materials Project

Abstract

MgGeO3 crystallizes in the orthorhombic Pbca 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 six GeO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.03–2.19 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six GeO4 tetrahedra, edges with three equivalent MgO6 octahedra, and an edgeedge with one GeO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 2.03–2.30 Å. There are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with five MgO6 octahedra, corners with two equivalent GeO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 32–63°. There are a spread of Ge–O bond distances ranging from 1.73–1.82 Å. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with seven MgO6 octahedra and corners with two equivalent GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–65°. There are a spread of Ge–O bond distances ranging from 1.72–1.83 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to one Mg2+ and two equivalent Ge4+ atoms. In the second O2- site, O2- is bonded to three Mg2+ and one Ge4+ atom to form a mixture of distorted edge and corner-sharing OMg3Ge tetrahedra. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one Ge4+ atom. In the fourth O2- site, O2- is bonded to three Mg2+ and one Ge4+ atom to form a mixture of distorted edge and corner-sharing OMg3Ge trigonal pyramids. In the fifth O2- site, O2- is bonded in a distorted T-shaped geometry to two Mg2+ and one Ge4+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+ and two equivalent Ge4+ atoms.