Materials Data on MnGeO3 by Materials Project
MnGeO3 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are two inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six GeO4 tetrahedra and edges with five MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.15–2.30 Å. In the second Mn2+ site, Mn2+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six GeO4 tetrahedra, edges with three equivalent MnO6 octahedra, and an edgeedge with one GeO4 tetrahedra. There are a spread of Mn–O bond distances ranging from 2.11–2.47 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 MnO6 octahedra, corners with two equivalent GeO4 tetrahedra, and an edgeedge with one MnO6 octahedra. The corner-sharing octahedra tilt angles range from 35–61°. There are a spread of Ge–O bond distances ranging from 1.74–1.82 Å. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with seven MnO6 octahedra and corners with two equivalent GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–70°. There are a spread of Ge–O bond distances ranging from 1.73–1.84 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded to three Mn2+ and one Ge4+ atom to form a mixture of distorted edge and corner-sharing OMn3Ge trigonal pyramids. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mn2+ and one Ge4+ atom. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to two Mn2+ and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mn2+ and two equivalent Ge4+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+ and two equivalent Ge4+ atoms. In the sixth O2- site, O2- is bonded to three Mn2+ and one Ge4+ atom to form a mixture of distorted edge and corner-sharing OMn3Ge trigonal pyramids.