Materials Data on NaCrAsCO7 by Materials Project

Abstract

NaCrCAsO7 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.22–2.96 Å. Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent AsO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.87–2.01 Å. C4+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of C–O bond distances ranging from 1.23–1.36 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with four equivalent CrO6 octahedra. The corner-sharing octahedra tilt angles range from 36–48°. There are a spread of As–O bond distances ranging from 1.71–1.73 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Na1+ and one C4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Cr4+, and one C4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Cr4+, and one C4+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr4+ and one As5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Cr4+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Cr4+, and one As5+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Cr4+, and one As5+ atom.