Fe13O15 crystallizes in the triclinic P-1 space group. There are seven inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(5), one O(6), two equivalent O(3), and two equivalent O(7) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 5-18°. In the second Fe site, Fe(2) is bonded to one O(2), one O(5), one O(7), one O(8), and two equivalent O(1) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 0-16°. 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 edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 6-16°. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(4), one O(5), one O(8), and two equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 0-18°. In the fifth Fe site, Fe(5) is bonded to one O(1), one O(3), one O(4), one O(7), and two equivalent O(6) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 5-14°. In the sixth Fe site, Fe(6) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 6-14°. In the seventh Fe site, Fe(7) is bonded to one O(1), one O(4), one O(5), one O(6), and two equivalent O(2) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Fe(4), one Fe(5), one Fe(7), and two equivalent Fe(2) atoms to form OFe5 square pyramids that share  a cornercorner with one O(6)Fe6 octahedra, corners with two equivalent O(2)Fe6 octahedra,  a cornercorner with one O(3)Fe5 square pyramid,  a cornercorner with one O(4)Fe5 square pyramid,  a cornercorner with one O(7)Fe5 square pyramid, corners with two equivalent O(5)Fe5 square pyramids,  an edgeedge with one O(6)Fe6 octahedra, edges with two equivalent O(2)Fe6 octahedra,  an edgeedge with one O(1)Fe5 square pyramid,  an edgeedge with one O(4)Fe5 square pyramid,  an edgeedge with one O(5)Fe5 square pyramid, and  an edgeedge with one O(7)Fe5 square pyramid. The corner-sharing octahedral tilt angles range from 3-12°. In the second O site, O(2) is bonded to one Fe(2), one Fe(3), two equivalent Fe(4), and two equivalent Fe(7) atoms to form OFe6 octahedra that share  a cornercorner with one O(6)Fe6 octahedra,  a cornercorner with one O(3)Fe5 square pyramid,  a cornercorner with one O(4)Fe5 square pyramid, corners with two equivalent O(1)Fe5 square pyramids,  an edgeedge with one O(6)Fe6 octahedra, edges with two equivalent O(2)Fe6 octahedra,  an edgeedge with one O(7)Fe5 square pyramid, edges with two equivalent O(1)Fe5 square pyramids, edges with two equivalent O(4)Fe5 square pyramids, and edges with three equivalent O(5)Fe5 square pyramids. The corner-sharing octahedral tilt angles are 10°. In the third O site, O(3) is bonded to one Fe(3), one Fe(5), one Fe(6), and two equivalent Fe(1) atoms to form OFe5 square pyramids that share  a cornercorner with one O(2)Fe6 octahedra,  a cornercorner with one O(6)Fe6 octahedra,  a cornercorner with one O(1)Fe5 square pyramid,  a cornercorner with one O(3)Fe5 square pyramid,  a cornercorner with one O(5)Fe5 square pyramid, corners with two equivalent O(4)Fe5 square pyramids, corners with two equivalent O(7)Fe5 square pyramids, edges with three equivalent O(6)Fe6 octahedra,  an edgeedge with one O(3)Fe5 square pyramid,  an edgeedge with one O(4)Fe5 square pyramid,  an edgeedge with one O(5)Fe5 square pyramid, and edges with two equivalent O(7)Fe5 square pyramids. The corner-sharing octahedral tilt angles are 8°. In the fourth O site, O(4) is bonded to one Fe(3), one Fe(4), one Fe(5), one Fe(6), and one Fe(7) atom to form OFe5 square pyramids that share  a cornercorner with one O(2)Fe6 octahedra,  a cornercorner with one O(1)Fe5 square pyramid,  a cornercorner with one O(4)Fe5 square pyramid,  a cornercorner with one O(5)Fe5 square pyramid, corners with two equivalent O(3)Fe5 square pyramids, corners with two equivalent O(7)Fe5 square pyramids, edges with two equivalent O(2)Fe6 octahedra, edges with three equivalent O(6)Fe6 octahedra,  an edgeedge with one O(1)Fe5 square pyramid,  an edgeedge with one O(3)Fe5 square pyramid, and  an edgeedge with one O(5)Fe5 square pyramid. The corner-sharing octahedral tilt angles are 10°. In the fifth O site, O(5) is bonded to one Fe(1), one Fe(2), one Fe(3), one Fe(4), and one Fe(7) atom to form OFe5 square pyramids that share  a cornercorner with one O(6)Fe6 octahedra,  a cornercorner with one O(3)Fe5 square pyramid,  a cornercorner with one O(4)Fe5 square pyramid, corners with two equivalent O(1)Fe5 square pyramids, corners with two equivalent O(7)Fe5 square pyramids,  an edgeedge with one O(6)Fe6 octahedra, edges with three equivalent O(2)Fe6 octahedra,  an edgeedge with one O(1)Fe5 square pyramid,  an edgeedge with one O(3)Fe5 square pyramid,  an edgeedge with one O(4)Fe5 square pyramid, and  an edgeedge with one O(7)Fe5 square pyramid. The corner-sharing octahedral tilt angles are 12°. In the sixth O site, O(6) is bonded to one Fe(1), one Fe(3), one Fe(6), one Fe(7), and two equivalent Fe(5) atoms to form OFe6 octahedra that share  a cornercorner with one O(2)Fe6 octahedra,  a cornercorner with one O(6)Fe6 octahedra,  a cornercorner with one O(1)Fe5 square pyramid,  a cornercorner with one O(3)Fe5 square pyramid,  a cornercorner with one O(5)Fe5 square pyramid,  a cornercorner with one O(7)Fe5 square pyramid,  an edgeedge with one O(2)Fe6 octahedra,  an edgeedge with one O(6)Fe6 octahedra,  an edgeedge with one O(1)Fe5 square pyramid,  an edgeedge with one O(5)Fe5 square pyramid, edges with two equivalent O(7)Fe5 square pyramids, edges with three equivalent O(3)Fe5 square pyramids, and edges with three equivalent O(4)Fe5 square pyramids. The corner-sharing octahedral tilt angles range from 0-10°. In the seventh O site, O(7) is bonded to one Fe(2), one Fe(3), one Fe(5), and two equivalent Fe(1) atoms to form OFe5 square pyramids that share  a cornercorner with one O(6)Fe6 octahedra,  a cornercorner with one O(1)Fe5 square pyramid, corners with two equivalent O(3)Fe5 square pyramids, corners with two equivalent O(4)Fe5 square pyramids, corners with two equivalent O(5)Fe5 square pyramids,  an edgeedge with one O(2)Fe6 octahedra, edges with two equivalent O(6)Fe6 octahedra,  an edgeedge with one O(1)Fe5 square pyramid,  an edgeedge with one O(5)Fe5 square pyramid,  an edgeedge with one O(7)Fe5 square pyramid, and edges with two equivalent O(3)Fe5 square pyramids. The corner-sharing octahedral tilt angles are 2°. In the eighth O site, O(8) is bonded in a square co-planar geometry to two equivalent Fe(2) and two equivalent Fe(4) atoms.
Fe13O15 crystallizes in the triclinic P-1 space group. There are seven inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(5), one O(6), two equivalent O(3), and two equivalent O(7) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 5-18°. The Fe(1)-O(5) bond length is 2.12 Å. The Fe(1)-O(6) bond length is 2.27 Å. There is one shorter (2.19 Å) and one longer (2.21 Å) Fe(1)-O(3) bond length. There is one shorter (2.14 Å) and one longer (2.16 Å) Fe(1)-O(7) bond length. In the second Fe site, Fe(2) is bonded to one O(2), one O(5), one O(7), one O(8), and two equivalent O(1) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 0-16°. The Fe(2)-O(2) bond length is 2.25 Å. The Fe(2)-O(5) bond length is 2.37 Å. The Fe(2)-O(7) bond length is 2.13 Å. The Fe(2)-O(8) bond length is 2.12 Å. There is one shorter (2.15 Å) and one longer (2.18 Å) Fe(2)-O(1) bond length. 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 edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 6-16°. The Fe(3)-O(2) bond length is 2.12 Å. The Fe(3)-O(3) bond length is 1.99 Å. The Fe(3)-O(4) bond length is 2.06 Å. The Fe(3)-O(5) bond length is 2.07 Å. The Fe(3)-O(6) bond length is 2.19 Å. The Fe(3)-O(7) bond length is 2.05 Å. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(4), one O(5), one O(8), and two equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 0-18°. The Fe(4)-O(1) bond length is 2.13 Å. The Fe(4)-O(4) bond length is 2.18 Å. The Fe(4)-O(5) bond length is 2.17 Å. The Fe(4)-O(8) bond length is 1.98 Å. There is one shorter (2.23 Å) and one longer (2.34 Å) Fe(4)-O(2) bond length. In the fifth Fe site, Fe(5) is bonded to one O(1), one O(3), one O(4), one O(7), and two equivalent O(6) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 5-14°. The Fe(5)-O(1) bond length is 2.13 Å. The Fe(5)-O(3) bond length is 2.14 Å. The Fe(5)-O(4) bond length is 2.22 Å. The Fe(5)-O(7) bond length is 2.17 Å. There is one shorter (2.15 Å) and one longer (2.22 Å) Fe(5)-O(6) bond length. In the sixth Fe site, Fe(6) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 6-14°. Both Fe(6)-O(3) bond lengths are 2.14 Å. Both Fe(6)-O(4) bond lengths are 2.17 Å. Both Fe(6)-O(6) bond lengths are 2.25 Å. In the seventh Fe site, Fe(7) is bonded to one O(1), one O(4), one O(5), one O(6), and two equivalent O(2) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. The Fe(7)-O(1) bond length is 1.99 Å. The Fe(7)-O(4) bond length is 2.05 Å. The Fe(7)-O(5) bond length is 2.04 Å. The Fe(7)-O(6) bond length is 2.08 Å. There is one shorter (2.12 Å) and one longer (2.24 Å) Fe(7)-O(2) bond length. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Fe(4), one Fe(5), one Fe(7), and two equivalent Fe(2) atoms to form OFe5 square pyramids that share  a cornercorner with one O(6)Fe6 octahedra, corners with two equivalent O(2)Fe6 octahedra,  a cornercorner with one O(3)Fe5 square pyramid,  a cornercorner with one O(4)Fe5 square pyramid,  a cornercorner with one O(7)Fe5 square pyramid, corners with two equivalent O(5)Fe5 square pyramids,  an edgeedge with one O(6)Fe6 octahedra, edges with two equivalent O(2)Fe6 octahedra,  an edgeedge with one O(1)Fe5 square pyramid,  an edgeedge with one O(4)Fe5 square pyramid,  an edgeedge with one O(5)Fe5 square pyramid, and  an edgeedge with one O(7)Fe5 square pyramid. The corner-sharing octahedral tilt angles range from 3-12°. In the second O site, O(2) is bonded to one Fe(2), one Fe(3), two equivalent Fe(4), and two equivalent Fe(7) atoms to form OFe6 octahedra that share  a cornercorner with one O(6)Fe6 octahedra,  a cornercorner with one O(3)Fe5 square pyramid,  a cornercorner with one O(4)Fe5 square pyramid, corners with two equivalent O(1)Fe5 square pyramids,  an edgeedge with one O(6)Fe6 octahedra, edges with two equivalent O(2)Fe6 octahedra,  an edgeedge with one O(7)Fe5 square pyramid, edges with two equivalent O(1)Fe5 square pyramids, edges with two equivalent O(4)Fe5 square pyramids, and edges with three equivalent O(5)Fe5 square pyramids. The corner-sharing octahedral tilt angles are 10°. In the third O site, O(3) is bonded to one Fe(3), one Fe(5), one Fe(6), and two equivalent Fe(1) atoms to form OFe5 square pyramids that share  a cornercorner with one O(2)Fe6 octahedra,  a cornercorner with one O(6)Fe6 octahedra,  a cornercorner with one O(1)Fe5 square pyramid,  a cornercorner with one O(3)Fe5 square pyramid,  a cornercorner with one O(5)Fe5 square pyramid, corners with two equivalent O(4)Fe5 square pyramids, corners with two equivalent O(7)Fe5 square pyramids, edges with three equivalent O(6)Fe6 octahedra,  an edgeedge with one O(3)Fe5 square pyramid,  an edgeedge with one O(4)Fe5 square pyramid,  an edgeedge with one O(5)Fe5 square pyramid, and edges with two equivalent O(7)Fe5 square pyramids. The corner-sharing octahedral tilt angles are 8°. In the fourth O site, O(4) is bonded to one Fe(3), one Fe(4), one Fe(5), one Fe(6), and one Fe(7) atom to form OFe5 square pyramids that share  a cornercorner with one O(2)Fe6 octahedra,  a cornercorner with one O(1)Fe5 square pyramid,  a cornercorner with one O(4)Fe5 square pyramid,  a cornercorner with one O(5)Fe5 square pyramid, corners with two equivalent O(3)Fe5 square pyramids, corners with two equivalent O(7)Fe5 square pyramids, edges with two equivalent O(2)Fe6 octahedra, edges with three equivalent O(6)Fe6 octahedra,  an edgeedge with one O(1)Fe5 square pyramid,  an edgeedge with one O(3)Fe5 square pyramid, and  an edgeedge with one O(5)Fe5 square pyramid. The corner-sharing octahedral tilt angles are 10°. In the fifth O site, O(5) is bonded to one Fe(1), one Fe(2), one Fe(3), one Fe(4), and one Fe(7) atom to form OFe5 square pyramids that share  a cornercorner with one O(6)Fe6 octahedra,  a cornercorner with one O(3)Fe5 square pyramid,  a cornercorner with one O(4)Fe5 square pyramid, corners with two equivalent O(1)Fe5 square pyramids, corners with two equivalent O(7)Fe5 square pyramids,  an edgeedge with one O(6)Fe6 octahedra, edges with three equivalent O(2)Fe6 octahedra,  an edgeedge with one O(1)Fe5 square pyramid,  an edgeedge with one O(3)Fe5 square pyramid,  an edgeedge with one O(4)Fe5 square pyramid, and  an edgeedge with one O(7)Fe5 square pyramid. The corner-sharing octahedral tilt angles are 12°. In the sixth O site, O(6) is bonded to one Fe(1), one Fe(3), one Fe(6), one Fe(7), and two equivalent Fe(5) atoms to form OFe6 octahedra that share  a cornercorner with one O(2)Fe6 octahedra,  a cornercorner with one O(6)Fe6 octahedra,  a cornercorner with one O(1)Fe5 square pyramid,  a cornercorner with one O(3)Fe5 square pyramid,  a cornercorner with one O(5)Fe5 square pyramid,  a cornercorner with one O(7)Fe5 square pyramid,  an edgeedge with one O(2)Fe6 octahedra,  an edgeedge with one O(6)Fe6 octahedra,  an edgeedge with one O(1)Fe5 square pyramid,  an edgeedge with one O(5)Fe5 square pyramid, edges with two equivalent O(7)Fe5 square pyramids, edges with three equivalent O(3)Fe5 square pyramids, and edges with three equivalent O(4)Fe5 square pyramids. The corner-sharing octahedral tilt angles range from 0-10°. In the seventh O site, O(7) is bonded to one Fe(2), one Fe(3), one Fe(5), and two equivalent Fe(1) atoms to form OFe5 square pyramids that share  a cornercorner with one O(6)Fe6 octahedra,  a cornercorner with one O(1)Fe5 square pyramid, corners with two equivalent O(3)Fe5 square pyramids, corners with two equivalent O(4)Fe5 square pyramids, corners with two equivalent O(5)Fe5 square pyramids,  an edgeedge with one O(2)Fe6 octahedra, edges with two equivalent O(6)Fe6 octahedra,  an edgeedge with one O(1)Fe5 square pyramid,  an edgeedge with one O(5)Fe5 square pyramid,  an edgeedge with one O(7)Fe5 square pyramid, and edges with two equivalent O(3)Fe5 square pyramids. The corner-sharing octahedral tilt angles are 2°. In the eighth O site, O(8) is bonded in a square co-planar geometry to two equivalent Fe(2) and two equivalent Fe(4) atoms.