DOI: 10.17188/1750976
title: Materials Data on Ba4Pr4Fe4Cu4O21 by Materials Project

description: Ba4Pr4Fe4Cu4O21 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, faces with two equivalent FeO6 octahedra, faces with four CuO5 square pyramids, and faces with two equivalent FeO5 trigonal bipyramids. There are a spread of Ba–O bond distances ranging from 2.81–3.19 Å. There are two inequivalent Pr+3.50+ sites. In the first Pr+3.50+ site, Pr+3.50+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are eight shorter (2.57 Å) and two longer (2.80 Å) Pr–O bond lengths. In the second Pr+3.50+ site, Pr+3.50+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Pr–O bond lengths are 2.52 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one FeO6 octahedra, a cornercorner with one CuO5 square pyramid, corners with four equivalent FeO5 trigonal bipyramids, and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Fe–O bond distances ranging from 1.88–2.08 Å. In the second Fe3+ site, Fe3+ is bonded to five O2- atoms to form distorted FeO5 trigonal bipyramids that share corners with four equivalent FeO6 octahedra, a cornercorner with one CuO5 square pyramid, and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 21°. There is one shorter (1.88 Å) and four longer (1.96 Å) Fe–O bond length. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to five O2- atoms to form CuO5 square pyramids that share a cornercorner with one FeO6 octahedra, corners with four equivalent CuO5 square pyramids, and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (1.98 Å) and one longer (2.37 Å) Cu–O bond lengths. In the second Cu2+ site, Cu2+ is bonded to five O2- atoms to form CuO5 square pyramids that share corners with four equivalent CuO5 square pyramids, a cornercorner with one FeO5 trigonal bipyramid, and faces with four equivalent BaO12 cuboctahedra. There are four shorter (2.01 Å) and one longer (2.17 Å) Cu–O bond lengths. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, two equivalent Pr+3.50+, and two Fe3+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Ba2+, two equivalent Pr+3.50+, and two Cu2+ atoms. In the third O2- site, O2- is bonded to four equivalent Ba2+, one Fe3+, and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OBa4FeCu octahedra. The corner-sharing octahedral tilt angles are 14°. In the fourth O2- site, O2- is bonded to four equivalent Ba2+, one Fe3+, and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OBa4FeCu octahedra. The corner-sharing octahedral tilt angles are 7°. In the fifth O2- site, O2- is bonded in a linear geometry to four equivalent Pr+3.50+ and two equivalent Fe3+ atoms.