Materials Data on Mg2BO3F by Materials Project
Mg2BO3F crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- and one F1- atom to form MgO5F octahedra that share corners with three equivalent MgO3F3 octahedra and edges with four MgO5F octahedra. The corner-sharing octahedra tilt angles range from 59–65°. There are a spread of Mg–O bond distances ranging from 2.02–2.16 Å. The Mg–F bond length is 2.18 Å. In the second Mg2+ site, Mg2+ is bonded to three O2- and three equivalent F1- atoms to form a mixture of edge and corner-sharing MgO3F3 octahedra. The corner-sharing octahedra tilt angles range from 59–65°. There are one shorter (2.05 Å) and two longer (2.07 Å) Mg–O bond lengths. There are one shorter (2.09 Å) and two longer (2.10 Å) Mg–F bond lengths. B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.36 Å) and two longer (1.40 Å) B–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Mg2+ and one B3+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one B3+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Mg2+ and one B3+ atom. F1- is bonded to four Mg2+ atoms to form a mixture of distorted edge and corner-sharing FMg4 tetrahedra.