Sr4Fe6O13 crystallizes in the orthorhombic Iba2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(2), one O(5), two equivalent O(3), two equivalent O(4), and three equivalent O(1) atoms. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(1), one O(6), two equivalent O(3), two equivalent O(4), and three equivalent O(2) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), two equivalent O(5), and two equivalent O(7) atoms to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Fe(3)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with two equivalent Fe(2)O5 trigonal bipyramids, and edges with three equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 13°. In the second Fe site, Fe(2) is bonded to one O(2), one O(5), and three equivalent O(6) atoms to form FeO5 trigonal bipyramids that share  a cornercorner with one Fe(3)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with four equivalent Fe(2)O5 trigonal bipyramids, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 6°. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted FeO6 octahedra that share corners with four equivalent Fe(3)O6 octahedra,  a cornercorner with one Fe(1)O5 trigonal bipyramid, and  a cornercorner with one Fe(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 3-14°. There are seven inequivalent O sites. In the first O site, O(7) is bonded to four equivalent Fe(1) atoms to form distorted OFe4 trigonal pyramids that share corners with four equivalent O(5)SrFe3 tetrahedra, edges with two equivalent O(5)SrFe3 tetrahedra, and edges with two equivalent O(7)Fe4 trigonal pyramids. In the second O site, O(1) is bonded in a 6-coordinate geometry to one Sr(2), three equivalent Sr(1), one Fe(1), and one Fe(3) atom. In the third O site, O(2) is bonded in a 6-coordinate geometry to one Sr(1), three equivalent Sr(2), one Fe(2), and one Fe(3) atom. In the fourth O site, O(3) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(3) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(4)Sr4Fe2 octahedra, corners with two equivalent O(5)SrFe3 tetrahedra, corners with two equivalent O(6)SrFe3 tetrahedra, edges with two equivalent O(4)Sr4Fe2 octahedra, faces with two equivalent O(3)Sr4Fe2 octahedra, and faces with two equivalent O(4)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 6-9°. In the fifth O site, O(4) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(3) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(3)Sr4Fe2 octahedra, corners with two equivalent O(5)SrFe3 tetrahedra, corners with two equivalent O(6)SrFe3 tetrahedra, edges with two equivalent O(3)Sr4Fe2 octahedra, faces with two equivalent O(3)Sr4Fe2 octahedra, and faces with two equivalent O(4)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 6-9°. In the sixth O site, O(5) is bonded to one Sr(1), one Fe(2), and two equivalent Fe(1) atoms to form distorted OSrFe3 tetrahedra that share corners with two equivalent O(3)Sr4Fe2 octahedra, corners with two equivalent O(4)Sr4Fe2 octahedra, corners with two equivalent O(5)SrFe3 tetrahedra, corners with three equivalent O(6)SrFe3 tetrahedra, corners with two equivalent O(7)Fe4 trigonal pyramids, and  an edgeedge with one O(7)Fe4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 25-71°. In the seventh O site, O(6) is bonded to one Sr(2) and three equivalent Fe(2) atoms to form distorted OSrFe3 tetrahedra that share corners with two equivalent O(3)Sr4Fe2 octahedra, corners with two equivalent O(4)Sr4Fe2 octahedra, corners with three equivalent O(5)SrFe3 tetrahedra, corners with four equivalent O(6)SrFe3 tetrahedra, and  an edgeedge with one O(6)SrFe3 tetrahedra. The corner-sharing octahedral tilt angles range from 26-66°.
Sr4Fe6O13 crystallizes in the orthorhombic Iba2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(2), one O(5), two equivalent O(3), two equivalent O(4), and three equivalent O(1) atoms. The Sr(1)-O(2) bond length is 2.88 Å. The Sr(1)-O(5) bond length is 2.65 Å. There is one shorter (2.59 Å) and one longer (2.61 Å) Sr(1)-O(3) bond length. There is one shorter (2.63 Å) and one longer (2.75 Å) Sr(1)-O(4) bond length. There are a spread of Sr(1)-O(1) bond distances ranging from 2.76-2.97 Å. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(1), one O(6), two equivalent O(3), two equivalent O(4), and three equivalent O(2) atoms. The Sr(2)-O(1) bond length is 2.77 Å. The Sr(2)-O(6) bond length is 2.49 Å. There is one shorter (2.72 Å) and one longer (2.78 Å) Sr(2)-O(3) bond length. There is one shorter (2.56 Å) and one longer (2.61 Å) Sr(2)-O(4) bond length. There are a spread of Sr(2)-O(2) bond distances ranging from 2.68-2.84 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), two equivalent O(5), and two equivalent O(7) atoms to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Fe(3)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with two equivalent Fe(2)O5 trigonal bipyramids, and edges with three equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 13°. The Fe(1)-O(1) bond length is 1.87 Å. There is one shorter (1.97 Å) and one longer (2.09 Å) Fe(1)-O(5) bond length. There is one shorter (2.01 Å) and one longer (2.19 Å) Fe(1)-O(7) bond length. In the second Fe site, Fe(2) is bonded to one O(2), one O(5), and three equivalent O(6) atoms to form FeO5 trigonal bipyramids that share  a cornercorner with one Fe(3)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with four equivalent Fe(2)O5 trigonal bipyramids, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 6°. The Fe(2)-O(2) bond length is 1.92 Å. The Fe(2)-O(5) bond length is 2.03 Å. There are a spread of Fe(2)-O(6) bond distances ranging from 2.02-2.14 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted FeO6 octahedra that share corners with four equivalent Fe(3)O6 octahedra,  a cornercorner with one Fe(1)O5 trigonal bipyramid, and  a cornercorner with one Fe(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 3-14°. The Fe(3)-O(1) bond length is 2.51 Å. The Fe(3)-O(2) bond length is 2.07 Å. Both Fe(3)-O(3) bond lengths are 1.95 Å. There is one shorter (1.96 Å) and one longer (1.97 Å) Fe(3)-O(4) bond length. There are seven inequivalent O sites. In the first O site, O(7) is bonded to four equivalent Fe(1) atoms to form distorted OFe4 trigonal pyramids that share corners with four equivalent O(5)SrFe3 tetrahedra, edges with two equivalent O(5)SrFe3 tetrahedra, and edges with two equivalent O(7)Fe4 trigonal pyramids. In the second O site, O(1) is bonded in a 6-coordinate geometry to one Sr(2), three equivalent Sr(1), one Fe(1), and one Fe(3) atom. In the third O site, O(2) is bonded in a 6-coordinate geometry to one Sr(1), three equivalent Sr(2), one Fe(2), and one Fe(3) atom. In the fourth O site, O(3) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(3) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(4)Sr4Fe2 octahedra, corners with two equivalent O(5)SrFe3 tetrahedra, corners with two equivalent O(6)SrFe3 tetrahedra, edges with two equivalent O(4)Sr4Fe2 octahedra, faces with two equivalent O(3)Sr4Fe2 octahedra, and faces with two equivalent O(4)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 6-9°. In the fifth O site, O(4) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(3) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(3)Sr4Fe2 octahedra, corners with two equivalent O(5)SrFe3 tetrahedra, corners with two equivalent O(6)SrFe3 tetrahedra, edges with two equivalent O(3)Sr4Fe2 octahedra, faces with two equivalent O(3)Sr4Fe2 octahedra, and faces with two equivalent O(4)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 6-9°. In the sixth O site, O(5) is bonded to one Sr(1), one Fe(2), and two equivalent Fe(1) atoms to form distorted OSrFe3 tetrahedra that share corners with two equivalent O(3)Sr4Fe2 octahedra, corners with two equivalent O(4)Sr4Fe2 octahedra, corners with two equivalent O(5)SrFe3 tetrahedra, corners with three equivalent O(6)SrFe3 tetrahedra, corners with two equivalent O(7)Fe4 trigonal pyramids, and  an edgeedge with one O(7)Fe4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 25-71°. In the seventh O site, O(6) is bonded to one Sr(2) and three equivalent Fe(2) atoms to form distorted OSrFe3 tetrahedra that share corners with two equivalent O(3)Sr4Fe2 octahedra, corners with two equivalent O(4)Sr4Fe2 octahedra, corners with three equivalent O(5)SrFe3 tetrahedra, corners with four equivalent O(6)SrFe3 tetrahedra, and  an edgeedge with one O(6)SrFe3 tetrahedra. The corner-sharing octahedral tilt angles range from 26-66°.