Materials Data on FeCu2As3O11 by Materials Project
FeCu2As3O11 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four equivalent CuO5 square pyramids and corners with two equivalent AsO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 2.01–2.03 Å. Cu2+ is bonded to five O2- atoms to form CuO5 square pyramids that share corners with two equivalent FeO6 octahedra, corners with two equivalent AsO4 tetrahedra, and an edgeedge with one CuO5 square pyramid. The corner-sharing octahedra tilt angles range from 46–50°. There are a spread of Cu–O bond distances ranging from 1.92–2.34 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.70–1.83 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent FeO6 octahedra and corners with four equivalent CuO5 square pyramids. The corner-sharing octahedral tilt angles are 54°. There are a spread of As–O bond distances ranging from 1.70–1.74 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Fe3+, one Cu2+, and one As5+ atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Cu2+ and one As5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Fe3+, one Cu2+, and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu2+, one As5+, and one O2- atom. The O–O bond length is 2.50 Å. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to one Fe3+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cu2+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a water-like geometry to two equivalent O2- atoms.