Materials Data on NaCuAsO4 by Materials Project

Abstract

NaCuAsO4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.39–3.12 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 pentagonal pyramids that share corners with four AsO4 tetrahedra, corners with two equivalent CuO5 trigonal bipyramids, an edgeedge with one AsO4 tetrahedra, and an edgeedge with one CuO5 trigonal bipyramid. There are a spread of Na–O bond distances ranging from 2.32–2.56 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to five O2- atoms to form CuO5 trigonal bipyramids that share corners with two equivalent NaO6 pentagonal pyramids, corners with five AsO4 tetrahedra, and an edgeedge with one NaO6 pentagonal pyramid. There are a spread of Cu–O bond distances ranging from 1.96–2.22 Å. In the second Cu2+ site, Cu2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Cu–O bond distances ranging from 1.91–2.39 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 NaO6 pentagonal pyramids and corners with three equivalent CuO5 trigonal bipyramids. There are a spread of As–O bond distances ranging from 1.71–1.79 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent NaO6 pentagonal pyramids, corners with two equivalent CuO5 trigonal bipyramids, and an edgeedge with one NaO6 pentagonal pyramid. There is two shorter (1.72 Å) and two longer (1.74 Å) As–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, two Cu2+, and one As5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Cu2+, and one As5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+, one Cu2+, and one As5+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Cu2+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+, one Cu2+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cu2+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Cu2+, and one As5+ atom. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+, one Cu2+, and one As5+ atom.