DOI: 10.17188/1322708
title: Materials Data on MgMn2CoO7 by Materials Project

description: MgMn2CoO7 crystallizes in the monoclinic P2_1/c 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 distorted MgO6 octahedra that share corners with four MnO4 tetrahedra, corners with two equivalent MnO5 trigonal bipyramids, an edgeedge with one MgO6 pentagonal pyramid, and an edgeedge with one CoO5 trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 2.13–2.43 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 pentagonal pyramids that share a cornercorner with one MnO6 octahedra, corners with three equivalent MnO4 tetrahedra, corners with two equivalent MnO5 trigonal bipyramids, an edgeedge with one MgO6 octahedra, and an edgeedge with one MnO6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Mg–O bond distances ranging from 2.06–2.22 Å. There are four inequivalent Mn+4.50+ sites. In the first Mn+4.50+ site, Mn+4.50+ is bonded to four O2- atoms to form MnO4 tetrahedra that share a cornercorner with one MnO6 octahedra, corners with two equivalent MgO6 octahedra, and corners with three equivalent MgO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 48–75°. There are a spread of Mn–O bond distances ranging from 1.65–1.76 Å. In the second Mn+4.50+ site, Mn+4.50+ is bonded to five O2- atoms to form distorted MnO5 trigonal bipyramids that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO6 pentagonal pyramids, a cornercorner with one MnO4 tetrahedra, corners with two equivalent CoO5 trigonal bipyramids, and an edgeedge with one MnO6 octahedra. The corner-sharing octahedra tilt angles range from 52–61°. There are a spread of Mn–O bond distances ranging from 1.79–1.99 Å. In the third Mn+4.50+ site, Mn+4.50+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share a cornercorner with one MgO6 pentagonal pyramid, corners with two MnO4 tetrahedra, a cornercorner with one CoO5 trigonal bipyramid, an edgeedge with one MgO6 pentagonal pyramid, an edgeedge with one MnO5 trigonal bipyramid, and an edgeedge with one CoO5 trigonal bipyramid. There are a spread of Mn–O bond distances ranging from 1.87–2.06 Å. In the fourth Mn+4.50+ site, Mn+4.50+ is bonded to four O2- atoms to form MnO4 tetrahedra that share a cornercorner with one MnO6 octahedra, corners with two equivalent MgO6 octahedra, a cornercorner with one MnO5 trigonal bipyramid, and corners with two equivalent CoO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 48–74°. There are a spread of Mn–O bond distances ranging from 1.71–1.79 Å. There are two inequivalent Co3+ sites. In the first Co3+ site, Co3+ is bonded to five O2- atoms to form distorted CoO5 trigonal bipyramids that share a cornercorner with one MnO6 octahedra, corners with two equivalent MnO4 tetrahedra, corners with two equivalent MnO5 trigonal bipyramids, an edgeedge with one MgO6 octahedra, and an edgeedge with one MnO6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are a spread of Co–O bond distances ranging from 1.82–2.11 Å. In the second Co3+ site, Co3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Co–O bond distances ranging from 1.77–2.25 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mg2+ and one Mn+4.50+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Mg2+, one Mn+4.50+, and one Co3+ atom. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Mg2+, one Mn+4.50+, and one Co3+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mn+4.50+ and one Co3+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Mn+4.50+, and one Co3+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Mg2+, one Mn+4.50+, and two Co3+ atoms. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to one Mg2+, one Mn+4.50+, and one Co3+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one Mn+4.50+ atom. In the ninth O2- site, O2- is bonded in a bent 120 degrees geometry to two Mn+4.50+ atoms. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+ and two Mn+4.50+ atoms. In the eleventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Mn+4.50+ and two Co3+ atoms. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+ and two Mn+4.50+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Mn+4.50+, and one Co3+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mn+4.50+ and one Co3+ atom.