Materials Data on BeCr2O4 by Materials Project

BeCr2O4 is Ilmenite-like structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Be2+ is bonded to four O2- atoms to form BeO4 tetrahedra that share corners with six CrO6 octahedra and edges with three CrO6 octahedra. The corner-sharing octahedra tilt angles range from 58–60°. There are a spread of Be–O bond distances ranging from 1.59–1.68 Å. There are two inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with two equivalent BeO4 tetrahedra, edges with four CrO6 octahedra, and edges with two equivalent BeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–58°. There are a spread of Cr–O bond distances ranging from 2.00–2.02 Å. In the second Cr3+ site, Cr3+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with eight CrO6 octahedra, corners with four equivalent BeO4 tetrahedra, edges with two equivalent CrO6 octahedra, and an edgeedge with one BeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–58°. There are a spread of Cr–O bond distances ranging from 2.01–2.07 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Be2+ and three Cr3+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Be2+ and three Cr3+ atoms. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Be2+ and three Cr3+ atoms.