Materials Data on BaCu2(AsO4)2 by Materials Project

Abstract

BaCu2(AsO4)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ba2+ is bonded to eight O2- atoms to form distorted BaO8 hexagonal bipyramids that share corners with four equivalent AsO4 tetrahedra, corners with four equivalent CuO5 trigonal bipyramids, edges with two equivalent BaO8 hexagonal bipyramids, edges with two equivalent AsO4 tetrahedra, and edges with two equivalent CuO5 trigonal bipyramids. There are a spread of Ba–O bond distances ranging from 2.78–2.98 Å. Cu2+ is bonded to five O2- atoms to form CuO5 trigonal bipyramids that share corners with two equivalent BaO8 hexagonal bipyramids, corners with five equivalent AsO4 tetrahedra, an edgeedge with one BaO8 hexagonal bipyramid, and an edgeedge with one CuO5 trigonal bipyramid. There are a spread of Cu–O bond distances ranging from 1.96–2.32 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent BaO8 hexagonal bipyramids, corners with five equivalent CuO5 trigonal bipyramids, and an edgeedge with one BaO8 hexagonal bipyramid. There are a spread of As–O bond distances ranging from 1.72–1.75 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Cu2+ and one As5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, one Cu2+, and one As5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ba2+, one Cu2+, and one As5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Cu2+, and one As5+ atom.