Materials Data on MgMnB2O5 by Materials Project
MgMnB2O5 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share edges with two equivalent MnO6 octahedra and edges with four equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.06–2.19 Å. Mn2+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share edges with two equivalent MgO6 octahedra and edges with two equivalent MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.09–2.39 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.35–1.42 Å. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.37 Å) and one longer (1.44 Å) B–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Mn2+ and one B3+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Mg2+ and one B3+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Mg2+, two equivalent Mn2+, and one B3+ atom. In the fourth O2- site, O2- is bonded to two equivalent Mg2+, one Mn2+, and one B3+ atom to form distorted corner-sharing OMg2MnB tetrahedra. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+ and two B3+ atoms.