Cu2FeBO5 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form FeO6 octahedra that share edges with two equivalent Fe(1)O6 octahedra and edges with two equivalent Cu(1)O6 octahedra. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(2) and four equivalent O(5) atoms to form distorted CuO6 octahedra that share edges with two equivalent Cu(1)O6 octahedra and edges with four equivalent Fe(1)O6 octahedra. In the second Cu site, Cu(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. In the third Cu site, Cu(3) is bonded in a distorted square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. B(1) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(5) atom. There are five inequivalent O sites. In the first O site, O(5) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Cu(1), and one B(1) atom. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Fe(1), one Cu(2), and one Cu(3) atom. In the third O site, O(2) is bonded to two equivalent Fe(1), one Cu(1), and one Cu(2) atom to form distorted corner-sharing OFe2Cu2 tetrahedra. In the fourth O site, O(3) is bonded in a 3-coordinate geometry to one Cu(3), two equivalent Cu(2), and one B(1) atom. In the fifth O site, O(4) is bonded in a 3-coordinate geometry to one Fe(1), two equivalent Cu(2), and one B(1) atom.
Cu2FeBO5 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form FeO6 octahedra that share edges with two equivalent Fe(1)O6 octahedra and edges with two equivalent Cu(1)O6 octahedra. The Fe(1)-O(4) bond length is 2.02 Å. The Fe(1)-O(5) bond length is 2.04 Å. There is one shorter (2.06 Å) and one longer (2.11 Å) Fe(1)-O(1) bond length. There is one shorter (2.04 Å) and one longer (2.08 Å) Fe(1)-O(2) bond length. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(2) and four equivalent O(5) atoms to form distorted CuO6 octahedra that share edges with two equivalent Cu(1)O6 octahedra and edges with four equivalent Fe(1)O6 octahedra. Both Cu(1)-O(2) bond lengths are 2.01 Å. There are two shorter (2.00 Å) and two longer (2.51 Å) Cu(1)-O(5) bond lengths. In the second Cu site, Cu(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. The Cu(2)-O(1) bond length is 2.02 Å. The Cu(2)-O(2) bond length is 1.94 Å. There is one shorter (2.02 Å) and one longer (2.59 Å) Cu(2)-O(3) bond length. There is one shorter (1.99 Å) and one longer (2.59 Å) Cu(2)-O(4) bond length. In the third Cu site, Cu(3) is bonded in a distorted square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. Both Cu(3)-O(1) bond lengths are 1.95 Å. Both Cu(3)-O(3) bond lengths are 1.98 Å. B(1) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(5) atom. The B(1)-O(3) bond length is 1.38 Å. The B(1)-O(4) bond length is 1.38 Å. The B(1)-O(5) bond length is 1.38 Å. There are five inequivalent O sites. In the first O site, O(5) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Cu(1), and one B(1) atom. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Fe(1), one Cu(2), and one Cu(3) atom. In the third O site, O(2) is bonded to two equivalent Fe(1), one Cu(1), and one Cu(2) atom to form distorted corner-sharing OFe2Cu2 tetrahedra. In the fourth O site, O(3) is bonded in a 3-coordinate geometry to one Cu(3), two equivalent Cu(2), and one B(1) atom. In the fifth O site, O(4) is bonded in a 3-coordinate geometry to one Fe(1), two equivalent Cu(2), and one B(1) atom.