Fe3BO5 crystallizes in the orthorhombic Pnma space group. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(6), and four equivalent O(4) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 18°. In the second Fe site, Fe(2) is bonded to one O(1), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 18-62°. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 58-62°. In the fourth Fe site, Fe(4) is bonded to one O(7), one O(8), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 18-60°. In the fifth Fe site, Fe(5) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(6), one O(7), and one O(8) atom. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(5) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Fe(2), two equivalent Fe(5), and one B(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Fe(1), two equivalent Fe(3), and one B(2) atom. In the third O site, O(3) is bonded to one Fe(2), one Fe(3), one Fe(4), and one Fe(5) atom to form distorted OFe4 tetrahedra that share corners with three equivalent O(4)Fe5 square pyramids, corners with three equivalent O(3)Fe4 tetrahedra, and  an edgeedge with one O(4)Fe5 square pyramid. In the fourth O site, O(4) is bonded to one Fe(2), one Fe(3), one Fe(4), and two equivalent Fe(1) atoms to form OFe5 square pyramids that share corners with two equivalent O(4)Fe5 square pyramids, corners with three equivalent O(3)Fe4 tetrahedra, edges with three equivalent O(4)Fe5 square pyramids, and  an edgeedge with one O(3)Fe4 tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Fe(2), two equivalent Fe(3), and one B(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Fe(3), and one B(1) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Fe(4), two equivalent Fe(3), and one B(1) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Fe(4), two equivalent Fe(5), and one B(1) atom.
Fe3BO5 crystallizes in the orthorhombic Pnma space group. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(6), and four equivalent O(4) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 18°. The Fe(1)-O(2) bond length is 2.16 Å. The Fe(1)-O(6) bond length is 2.13 Å. There are two shorter (2.08 Å) and two longer (2.10 Å) Fe(1)-O(4) bond lengths. In the second Fe site, Fe(2) is bonded to one O(1), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 18-62°. The Fe(2)-O(1) bond length is 2.16 Å. The Fe(2)-O(5) bond length is 2.15 Å. Both Fe(2)-O(3) bond lengths are 2.06 Å. Both Fe(2)-O(4) bond lengths are 2.12 Å. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 58-62°. The Fe(3)-O(2) bond length is 2.16 Å. The Fe(3)-O(3) bond length is 1.96 Å. The Fe(3)-O(4) bond length is 2.09 Å. The Fe(3)-O(5) bond length is 2.20 Å. The Fe(3)-O(6) bond length is 2.23 Å. The Fe(3)-O(7) bond length is 2.14 Å. In the fourth Fe site, Fe(4) is bonded to one O(7), one O(8), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 18-60°. The Fe(4)-O(7) bond length is 2.16 Å. The Fe(4)-O(8) bond length is 2.13 Å. Both Fe(4)-O(3) bond lengths are 2.05 Å. Both Fe(4)-O(4) bond lengths are 2.11 Å. In the fifth Fe site, Fe(5) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 58°. Both Fe(5)-O(1) bond lengths are 2.16 Å. Both Fe(5)-O(3) bond lengths are 2.04 Å. Both Fe(5)-O(8) bond lengths are 2.18 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(6), one O(7), and one O(8) atom. The B(1)-O(6) bond length is 1.38 Å. The B(1)-O(7) bond length is 1.39 Å. The B(1)-O(8) bond length is 1.39 Å. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(5) atom. The B(2)-O(1) bond length is 1.39 Å. The B(2)-O(2) bond length is 1.39 Å. The B(2)-O(5) bond length is 1.38 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Fe(2), two equivalent Fe(5), and one B(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Fe(1), two equivalent Fe(3), and one B(2) atom. In the third O site, O(3) is bonded to one Fe(2), one Fe(3), one Fe(4), and one Fe(5) atom to form distorted OFe4 tetrahedra that share corners with three equivalent O(4)Fe5 square pyramids, corners with three equivalent O(3)Fe4 tetrahedra, and  an edgeedge with one O(4)Fe5 square pyramid. In the fourth O site, O(4) is bonded to one Fe(2), one Fe(3), one Fe(4), and two equivalent Fe(1) atoms to form OFe5 square pyramids that share corners with two equivalent O(4)Fe5 square pyramids, corners with three equivalent O(3)Fe4 tetrahedra, edges with three equivalent O(4)Fe5 square pyramids, and  an edgeedge with one O(3)Fe4 tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Fe(2), two equivalent Fe(3), and one B(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Fe(3), and one B(1) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Fe(4), two equivalent Fe(3), and one B(1) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Fe(4), two equivalent Fe(5), and one B(1) atom.