Materials Data on Be(FeO2)2 by Materials Project
BeFe2O4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Be2+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.52 Å) and two longer (1.56 Å) Be–O bond length. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 54–62°. There are a spread of Fe–O bond distances ranging from 1.97–2.13 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 54–62°. There are a spread of Fe–O bond distances ranging from 2.05–2.09 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Fe3+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Be2+ and two equivalent Fe3+ atoms. In the third O2- site, O2- is bonded to one Be2+ and three Fe3+ atoms to form distorted corner-sharing OBeFe3 tetrahedra. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Be2+ and three Fe3+ atoms.