Materials Data on MgMn2O4 by Materials Project

Abstract

MgMn2O4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Mg2+ is bonded to five O2- atoms to form MgO5 square pyramids that share corners with four equivalent MnO6 octahedra, corners with four equivalent MnO5 square pyramids, an edgeedge with one MnO5 square pyramid, edges with two equivalent MgO5 square pyramids, and a faceface with one MnO6 octahedra. The corner-sharing octahedra tilt angles range from 36–62°. There are two shorter (2.04 Å) and three longer (2.08 Å) Mg–O bond lengths. There are two inequivalent Mn3+ sites. In the first Mn3+ site, Mn3+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with four equivalent MnO6 octahedra, corners with four equivalent MgO5 square pyramids, an edgeedge with one MgO5 square pyramid, and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 50–52°. There are a spread of Mn–O bond distances ranging from 1.93–2.07 Å. In the second Mn3+ site, Mn3+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with four equivalent MgO5 square pyramids, corners with four equivalent MnO5 square pyramids, edges with four equivalent MnO6 octahedra, and a faceface with one MgO5 square pyramid. There are a spread of Mn–O bond distances ranging from 1.90–2.33 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mg2+ and three Mn3+ atoms to form distorted OMgMn3 tetrahedra that share corners with two equivalent OMgMn3 tetrahedra, a cornercorner with one OMg2Mn3 trigonal bipyramid, and edges with two equivalent OMg2Mn3 trigonal bipyramids. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn3+ atoms. In the third O2- site, O2- is bonded in a square co-planar geometry to two equivalent Mg2+ and two equivalent Mn3+ atoms. In the fourth O2- site, O2- is bonded to two equivalent Mg2+ and three equivalent Mn3+ atoms to form distorted OMg2Mn3 trigonal bipyramids that share a cornercorner with one OMgMn3 tetrahedra, edges with two equivalent OMgMn3 tetrahedra, and edges with four equivalent OMg2Mn3 trigonal bipyramids.