Materials Data on MgMn2O4 by Materials Project

MgMn2O4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Mg2+ is bonded in a 5-coordinate geometry to seven O2- atoms. There are a spread of Mg–O bond distances ranging from 2.05–2.74 Å. There are two inequivalent Mn3+ sites. In the first Mn3+ site, Mn3+ is bonded to five O2- atoms to form MnO5 trigonal bipyramids that share corners with four equivalent MnO6 octahedra, corners with two equivalent MnO5 trigonal bipyramids, and an edgeedge with one MnO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 51–64°. There are a spread of Mn–O bond distances ranging from 1.94–2.10 Å. In the second Mn3+ site, Mn3+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with four equivalent MnO5 trigonal bipyramids and edges with four equivalent MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.94–2.62 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three equivalent Mn3+ atoms. In the second O2- site, O2- is bonded to two equivalent Mg2+ and three Mn3+ atoms to form distorted OMg2Mn3 trigonal pyramids that share corners with four equivalent OMg2Mn2 tetrahedra, corners with four equivalent OMg2Mn3 trigonal pyramids, and edges with two equivalent OMg2Mn2 tetrahedra. In the third O2- site, O2- is bonded to two equivalent Mg2+ and two equivalent Mn3+ atoms to form OMg2Mn2 tetrahedra that share corners with two equivalent OMg2Mn2 tetrahedra, corners with four equivalent OMg2Mn3 trigonal pyramids, an edgeedge with one OMg2Mn2 tetrahedra, and edges with two equivalent OMg2Mn3 trigonal pyramids. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Mg2+ and three Mn3+ atoms.