Fe3BO6 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form distorted FeO6 octahedra that share corners with eight equivalent Fe(2)O6 octahedra, corners with two equivalent B(1)O4 tetrahedra, edges with two equivalent Fe(2)O6 octahedra, and  an edgeedge with one B(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-64°. In the second Fe site, Fe(2) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with four equivalent Fe(1)O6 octahedra, corners with two equivalent B(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and  an edgeedge with one B(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-64°. B(1) is bonded to one O(1), one O(3), and two equivalent O(4) atoms to form BO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-60°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Fe(2), and one B(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Fe(2), and one B(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Fe(2), and one B(1) atom.
Fe3BO6 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form distorted FeO6 octahedra that share corners with eight equivalent Fe(2)O6 octahedra, corners with two equivalent B(1)O4 tetrahedra, edges with two equivalent Fe(2)O6 octahedra, and  an edgeedge with one B(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-64°. The Fe(1)-O(1) bond length is 2.03 Å. The Fe(1)-O(3) bond length is 2.25 Å. Both Fe(1)-O(2) bond lengths are 1.90 Å. Both Fe(1)-O(4) bond lengths are 2.15 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with four equivalent Fe(1)O6 octahedra, corners with two equivalent B(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and  an edgeedge with one B(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-64°. The Fe(2)-O(1) bond length is 2.12 Å. The Fe(2)-O(3) bond length is 2.12 Å. There is one shorter (1.92 Å) and one longer (1.95 Å) Fe(2)-O(2) bond length. There is one shorter (2.00 Å) and one longer (2.08 Å) Fe(2)-O(4) bond length. B(1) is bonded to one O(1), one O(3), and two equivalent O(4) atoms to form BO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-60°. The B(1)-O(1) bond length is 1.49 Å. The B(1)-O(3) bond length is 1.44 Å. Both B(1)-O(4) bond lengths are 1.51 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Fe(2), and one B(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Fe(2), and one B(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Fe(2), and one B(1) atom.