Materials Data on Na2CuAsCO7 by Materials Project

Abstract

Na2CuCAsO7 crystallizes in the monoclinic P2_1/m 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 2.28–2.68 Å. Cu3+ is bonded to six O2- atoms to form distorted CuO6 octahedra that share corners with four equivalent AsO4 tetrahedra. There are a spread of Cu–O bond distances ranging from 2.00–2.24 Å. C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.26 Å) and two longer (1.30 Å) C–O bond length. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with four equivalent CuO6 octahedra. The corner-sharing octahedra tilt angles range from 46–59°. There are a spread of As–O bond distances ranging from 1.71–1.74 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one C4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to two equivalent Na1+, one Cu3+, and one C4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Cu3+, and one C4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Cu3+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Na1+, one Cu3+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Cu3+, and one As5+ atom.