Materials Data on CrAsO4 by Materials Project
CrAsO4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Cr3+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six equivalent AsO4 tetrahedra and edges with two equivalent CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.97–2.11 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with six equivalent CrO6 octahedra. The corner-sharing octahedra tilt angles range from 54–58°. There are a spread of As–O bond distances ranging from 1.70–1.77 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr3+ and one As5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cr3+ and one As5+ atom. In the third O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Cr3+ and one As5+ atom.