DOI: 10.17188/1318565
title: Materials Data on MgMn2O4 by Materials Project

description: MgMn2O4 crystallizes in the triclinic P-1 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 pentagonal pyramids that share corners with six MnO6 octahedra, edges with six MnO6 octahedra, and edges with two equivalent MgO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 3–20°. There are a spread of Mg–O bond distances ranging from 2.13–2.29 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 pentagonal pyramids that share corners with twelve MnO6 octahedra, edges with two equivalent MgO6 pentagonal pyramids, and faces with two MnO6 octahedra. The corner-sharing octahedra tilt angles range from 40–55°. There are a spread of Mg–O bond distances ranging from 2.08–2.25 Å. There are six inequivalent Mn3+ sites. In the first Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with five MgO6 pentagonal pyramids, edges with six MnO6 octahedra, an edgeedge with one MgO6 pentagonal pyramid, and a faceface with one MgO6 pentagonal pyramid. There are a spread of Mn–O bond distances ranging from 1.88–2.32 Å. In the second Mn3+ site, Mn3+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with five MgO6 pentagonal pyramids, edges with six MnO6 octahedra, an edgeedge with one MgO6 pentagonal pyramid, and a faceface with one MgO6 pentagonal pyramid. There are a spread of Mn–O bond distances ranging from 1.89–2.35 Å. In the third Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four equivalent MgO6 pentagonal pyramids, edges with six MnO6 octahedra, and edges with two equivalent MgO6 pentagonal pyramids. There are a spread of Mn–O bond distances ranging from 1.96–2.20 Å. In the fourth Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four equivalent MgO6 pentagonal pyramids, edges with six MnO6 octahedra, and edges with two equivalent MgO6 pentagonal pyramids. There are a spread of Mn–O bond distances ranging from 1.96–2.18 Å. In the fifth Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four equivalent MgO6 pentagonal pyramids, edges with six MnO6 octahedra, and edges with two equivalent MgO6 pentagonal pyramids. There are a spread of Mn–O bond distances ranging from 1.97–2.21 Å. In the sixth Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four equivalent MgO6 pentagonal pyramids, edges with six MnO6 octahedra, and edges with two equivalent MgO6 pentagonal pyramids. There are a spread of Mn–O bond distances ranging from 1.97–2.21 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mg2+ and three Mn3+ atoms to form distorted OMgMn3 trigonal pyramids that share corners with four OMg2Mn3 trigonal bipyramids, corners with three OMgMn3 trigonal pyramids, and edges with four OMg2Mn3 trigonal bipyramids. In the second O2- site, O2- is bonded to one Mg2+ and three Mn3+ atoms to form distorted OMgMn3 trigonal pyramids that share corners with four OMg2Mn3 trigonal bipyramids, corners with six OMgMn3 trigonal pyramids, edges with four OMg2Mn3 trigonal bipyramids, and an edgeedge with one OMgMn3 trigonal pyramid. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Mn3+ atoms. In the fourth O2- site, O2- is bonded to one Mg2+ and three Mn3+ atoms to form distorted OMgMn3 trigonal pyramids that share corners with four OMg2Mn3 trigonal bipyramids, corners with five OMgMn3 trigonal pyramids, edges with four OMg2Mn3 trigonal bipyramids, and an edgeedge with one OMgMn3 trigonal pyramid. In the fifth O2- site, O2- is bonded to two Mg2+ and three Mn3+ atoms to form distorted OMg2Mn3 trigonal bipyramids that share corners with five OMg2Mn3 trigonal bipyramids, corners with three OMgMn3 trigonal pyramids, edges with four OMg2Mn3 trigonal bipyramids, and edges with two equivalent OMgMn3 trigonal pyramids. In the sixth O2- site, O2- is bonded to two Mg2+ and three Mn3+ atoms to form distorted OMg2Mn3 trigonal bipyramids that share corners with five OMg2Mn3 trigonal bipyramids, corners with three OMgMn3 trigonal pyramids, edges with four OMg2Mn3 trigonal bipyramids, and edges with four OMgMn3 trigonal pyramids. In the seventh O2- site, O2- is bonded to two Mg2+ and three Mn3+ atoms to form distorted OMg2Mn3 trigonal bipyramids that share corners with five OMg2Mn3 trigonal bipyramids, corners with three OMgMn3 trigonal pyramids, edges with four OMg2Mn3 trigonal bipyramids, and edges with two equivalent OMgMn3 trigonal pyramids. In the eighth O2- site, O2- is bonded to two Mg2+ and three Mn3+ atoms to form distorted OMg2Mn3 trigonal bipyramids that share corners with five OMg2Mn3 trigonal bipyramids, corners with three OMgMn3 trigonal pyramids, edges with four OMg2Mn3 trigonal bipyramids, and edges with four OMgMn3 trigonal pyramids.