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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

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.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CrAsO5 by Materials Project

CrAsO5 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. Cr5+ is bonded to five O2- atoms to form distorted CrO5 trigonal bipyramids that share corners with four equivalent AsO4 tetrahedra and corners with two equivalent CrO5 trigonal bipyramids. There are a spread of Cr–O bond distances ranging from 1.57–2.09 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with four equivalent CrO5 trigonal bipyramids. There are a spread of As–O bond distances ranging from 1.63–1.83 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Cr5+ atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Cr5+ and one As5+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one As5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr5+ and one As5+ atom. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr5+ and one As5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr2As6O19 by Materials Project

Cr2As6O19 crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six AsO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.98–2.00 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent CrO6 octahedra and corners with two equivalent AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–53°. There is two shorter (1.68 Å) and two longer (1.78 Å) As–O bond length. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent CrO6 octahedra and a cornercorner with one AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of As–O bond distances ranging from 1.72–1.78 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent As5+ atoms. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr4+ and one As5+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent As5+ atoms. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent As5+ atoms. In the fifth O2- site, O2- is bonded in a single-bond geometry to one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr4+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr4+ and one As5+ atom.

36 MATERIALS SCIENCE↗