Materials Data on Mg14Ge5O24 by Materials Project

Abstract

Mg14Ge5O24 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are six 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 six MgO6 octahedra. There are two shorter (2.02 Å) and four longer (2.14 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent GeO6 octahedra, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–13°. All Mg–O bond lengths are 2.15 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, corners with four GeO4 tetrahedra, an edgeedge with one GeO6 octahedra, and edges with four MgO6 octahedra. The corner-sharing octahedra tilt angles range from 13–59°. There are a spread of Mg–O bond distances ranging from 2.06–2.25 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with five MgO6 octahedra, corners with three GeO4 tetrahedra, edges with five MgO6 octahedra, and an edgeedge with one GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 2–56°. There are a spread of Mg–O bond distances ranging from 2.02–2.31 Å. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with three equivalent MgO6 octahedra, corners with three GeO4 tetrahedra, an edgeedge with one GeO6 octahedra, and edges with seven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–10°. There are a spread of Mg–O bond distances ranging from 2.05–2.15 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with five MgO6 octahedra, a cornercorner with one GeO4 tetrahedra, an edgeedge with one GeO6 octahedra, edges with six MgO6 octahedra, and an edgeedge with one GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 2–59°. There are a spread of Mg–O bond distances ranging from 2.09–2.17 Å. There are three inequivalent Ge4+ sites. In the first Ge4+ site, 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 57–60°. There are a spread of Ge–O bond distances ranging from 1.74–1.79 Å. In the second Ge4+ site, Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share edges with twelve MgO6 octahedra. There is four shorter (1.93 Å) and two longer (1.95 Å) Ge–O bond length. In the third Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with twelve MgO6 octahedra. The corner-sharing octahedra tilt angles range from 53–59°. There is one shorter (1.80 Å) and three longer (1.81 Å) Ge–O bond length. There are nine 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 four Mg2+ and one Ge4+ atom to form OMg4Ge square pyramids that share a cornercorner with one OMg4Ge square pyramid, corners with two equivalent OMg3Ge trigonal pyramids, edges with two equivalent OMg6 octahedra, and edges with four equivalent OMg4Ge square pyramids. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one Ge4+ atom. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one Ge4+ atom. In the sixth O2- site, O2- is bonded to three Mg2+ and one Ge4+ atom to form distorted OMg3Ge trigonal pyramids that share corners with four OMg4Ge square pyramids, a cornercorner with one OMg3Ge trigonal pyramid, and an edgeedge with one OMg6 octahedra. In the seventh O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share a cornercorner with one OMg6 octahedra, edges with six OMg4Ge square pyramids, and an edgeedge with one OMg3Ge trigonal pyramid. The corner-sharing octahedral tilt angles are 0°. In the eighth O2- site, O2- is bonded to four Mg2+ and one Ge4+ atom to form OMg4Ge square pyramids that share corners with three equivalent OMg4Ge square pyramids, a cornercorner with one OMg3Ge trigonal pyramid, edges with two equivalent OMg6 octahedra, and edges with four OMg4Ge square pyramids. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one Ge4+ atom.