Materials Data on Li2CrAsCO7 by Materials Project

Abstract

Li2CrCAsO7 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.04–2.76 Å. Cr3+ 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 1.98–2.07 Å. C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.26 Å) and two longer (1.32 Å) C–O bond length. 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 47–60°. There are a spread of As–O bond distances ranging from 1.70–1.73 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Li1+ and one C4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to two equivalent Li1+, one Cr3+, and one C4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Li1+, one Cr3+, and one C4+ atom. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+, one Cr3+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li1+, one Cr3+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Li1+, one Cr3+, and one As5+ atom.