Fe(BO2)2 crystallizes in the triclinic P-1 space group. Fe(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form FeO6 octahedra that share corners with six equivalent B(1)O4 tetrahedra, corners with six equivalent B(2)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. There are two inequivalent B sites. In the first B site, B(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form BO4 tetrahedra that share corners with six equivalent Fe(1)O6 octahedra, corners with two equivalent B(2)O4 tetrahedra, and  an edgeedge with one B(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-62°. In the second B site, B(2) is bonded to one O(3), one O(4), and two equivalent O(1) atoms to form BO4 tetrahedra that share corners with six equivalent Fe(1)O6 octahedra, corners with two equivalent B(1)O4 tetrahedra, and  an edgeedge with one B(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-60°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Fe(1) and two equivalent B(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Fe(1) and two equivalent B(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one B(1), and one B(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one B(1), and one B(2) atom.
Fe(BO2)2 crystallizes in the triclinic P-1 space group. Fe(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form FeO6 octahedra that share corners with six equivalent B(1)O4 tetrahedra, corners with six equivalent B(2)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. The Fe(1)-O(3) bond length is 2.08 Å. The Fe(1)-O(4) bond length is 2.22 Å. There is one shorter (2.07 Å) and one longer (2.13 Å) Fe(1)-O(1) bond length. There is one shorter (2.14 Å) and one longer (2.18 Å) Fe(1)-O(2) bond length. There are two inequivalent B sites. In the first B site, B(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form BO4 tetrahedra that share corners with six equivalent Fe(1)O6 octahedra, corners with two equivalent B(2)O4 tetrahedra, and  an edgeedge with one B(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-62°. The B(1)-O(3) bond length is 1.45 Å. The B(1)-O(4) bond length is 1.44 Å. There is one shorter (1.50 Å) and one longer (1.54 Å) B(1)-O(2) bond length. In the second B site, B(2) is bonded to one O(3), one O(4), and two equivalent O(1) atoms to form BO4 tetrahedra that share corners with six equivalent Fe(1)O6 octahedra, corners with two equivalent B(1)O4 tetrahedra, and  an edgeedge with one B(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-60°. The B(2)-O(3) bond length is 1.45 Å. The B(2)-O(4) bond length is 1.44 Å. There is one shorter (1.51 Å) and one longer (1.53 Å) B(2)-O(1) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Fe(1) and two equivalent B(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Fe(1) and two equivalent B(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one B(1), and one B(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one B(1), and one B(2) atom.