Ba4Y2FeCu5O14 crystallizes in the monoclinic C2/m space group. Ba(1) is bonded in a 10-coordinate geometry to one O(3), one O(4), two equivalent O(1), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. Y(1) is bonded in a body-centered cubic geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(5) atoms. Fe(1) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(6) atoms. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(5) atoms to form corner-sharing CuO5 square pyramids. In the second Cu site, Cu(2) is bonded to one O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted corner-sharing CuO5 square pyramids. In the third Cu site, Cu(3) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(6) atoms. There are six inequivalent O sites. In the first O site, O(6) is bonded in a 2-coordinate geometry to four equivalent Ba(1), one Fe(1), and one Cu(3) atom. In the second O site, O(1) is bonded to four equivalent Ba(1), one Cu(1), and one Cu(3) atom to form distorted OBa4Cu2 octahedra that share  a cornercorner with one O(1)Ba4Cu2 octahedra, corners with four equivalent O(2)Ba4FeCu octahedra, edges with two equivalent O(1)Ba4Cu2 octahedra, and edges with two equivalent O(2)Ba4FeCu octahedra. The corner-sharing octahedral tilt angles range from 0-15°. In the third O site, O(2) is bonded to four equivalent Ba(1), one Fe(1), and one Cu(2) atom to form distorted OBa4FeCu octahedra that share  a cornercorner with one O(2)Ba4FeCu octahedra, corners with four equivalent O(1)Ba4Cu2 octahedra, edges with two equivalent O(1)Ba4Cu2 octahedra, and edges with two equivalent O(2)Ba4FeCu octahedra. The corner-sharing octahedral tilt angles range from 0-15°. In the fourth O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Y(1), and two equivalent Cu(1) atoms. In the fifth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Y(1), and two equivalent Cu(2) atoms. In the sixth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Y(1), one Cu(1), and one Cu(2) atom.
Ba4Y2FeCu5O14 crystallizes in the monoclinic C2/m space group. Ba(1) is bonded in a 10-coordinate geometry to one O(3), one O(4), two equivalent O(1), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. The Ba(1)-O(3) bond length is 3.01 Å. The Ba(1)-O(4) bond length is 3.04 Å. Both Ba(1)-O(1) bond lengths are 2.75 Å. Both Ba(1)-O(2) bond lengths are 2.77 Å. There is one shorter (3.01 Å) and one longer (3.02 Å) Ba(1)-O(5) bond length. There is one shorter (2.80 Å) and one longer (3.11 Å) Ba(1)-O(6) bond length. Y(1) is bonded in a body-centered cubic geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(5) atoms. Both Y(1)-O(3) bond lengths are 2.42 Å. Both Y(1)-O(4) bond lengths are 2.41 Å. All Y(1)-O(5) bond lengths are 2.40 Å. Fe(1) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(6) atoms. Both Fe(1)-O(2) bond lengths are 1.87 Å. Both Fe(1)-O(6) bond lengths are 1.97 Å. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(5) atoms to form corner-sharing CuO5 square pyramids. The Cu(1)-O(1) bond length is 2.40 Å. Both Cu(1)-O(3) bond lengths are 1.94 Å. Both Cu(1)-O(5) bond lengths are 1.96 Å. In the second Cu site, Cu(2) is bonded to one O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted corner-sharing CuO5 square pyramids. The Cu(2)-O(2) bond length is 2.42 Å. Both Cu(2)-O(4) bond lengths are 1.95 Å. Both Cu(2)-O(5) bond lengths are 1.96 Å. In the third Cu site, Cu(3) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(6) atoms. Both Cu(3)-O(1) bond lengths are 1.88 Å. Both Cu(3)-O(6) bond lengths are 1.95 Å. There are six inequivalent O sites. In the first O site, O(6) is bonded in a 2-coordinate geometry to four equivalent Ba(1), one Fe(1), and one Cu(3) atom. In the second O site, O(1) is bonded to four equivalent Ba(1), one Cu(1), and one Cu(3) atom to form distorted OBa4Cu2 octahedra that share  a cornercorner with one O(1)Ba4Cu2 octahedra, corners with four equivalent O(2)Ba4FeCu octahedra, edges with two equivalent O(1)Ba4Cu2 octahedra, and edges with two equivalent O(2)Ba4FeCu octahedra. The corner-sharing octahedral tilt angles range from 0-15°. In the third O site, O(2) is bonded to four equivalent Ba(1), one Fe(1), and one Cu(2) atom to form distorted OBa4FeCu octahedra that share  a cornercorner with one O(2)Ba4FeCu octahedra, corners with four equivalent O(1)Ba4Cu2 octahedra, edges with two equivalent O(1)Ba4Cu2 octahedra, and edges with two equivalent O(2)Ba4FeCu octahedra. The corner-sharing octahedral tilt angles range from 0-15°. In the fourth O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Y(1), and two equivalent Cu(1) atoms. In the fifth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Y(1), and two equivalent Cu(2) atoms. In the sixth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Y(1), one Cu(1), and one Cu(2) atom.