Sr4Fe4O11 crystallizes in the orthorhombic Pnnm space group. Sr(1) is bonded in a distorted q6 geometry to one O(2), one O(3), one O(5), two equivalent O(4), two equivalent O(6), and four equivalent O(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with four equivalent Fe(2)O5 square pyramids. The corner-sharing octahedra are not tilted. In the second Fe site, Fe(2) is bonded to one O(2), one O(4), one O(6), and two equivalent O(1) atoms to form FeO5 square pyramids that share corners with four equivalent Fe(1)O6 octahedra and  a cornercorner with one Fe(2)O5 square pyramid. The corner-sharing octahedral tilt angles range from 2-14°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded to four equivalent Sr(1) and two equivalent Fe(2) atoms to form a mixture of distorted corner and edge-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 11-60°. In the third O site, O(3) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form a mixture of distorted face, corner, and edge-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles are 4°. In the fourth O site, O(4) is bonded to four equivalent Sr(1), one Fe(1), and one Fe(2) atom to form a mixture of distorted face, corner, and edge-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 4-60°. In the fifth O site, O(5) is bonded in a distorted linear geometry to four equivalent Sr(1) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded in a distorted linear geometry to four equivalent Sr(1), one Fe(1), and one Fe(2) atom.
Sr4Fe4O11 crystallizes in the orthorhombic Pnnm space group. Sr(1) is bonded in a distorted q6 geometry to one O(2), one O(3), one O(5), two equivalent O(4), two equivalent O(6), and four equivalent O(1) atoms. The Sr(1)-O(2) bond length is 2.83 Å. The Sr(1)-O(3) bond length is 2.73 Å. The Sr(1)-O(5) bond length is 2.78 Å. There is one shorter (2.77 Å) and one longer (2.78 Å) Sr(1)-O(4) bond length. There is one shorter (2.72 Å) and one longer (2.82 Å) Sr(1)-O(6) bond length. There are a spread of Sr(1)-O(1) bond distances ranging from 2.69-2.89 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with four equivalent Fe(2)O5 square pyramids. The corner-sharing octahedra are not tilted. The Fe(1)-O(3) bond length is 1.96 Å. The Fe(1)-O(4) bond length is 2.02 Å. The Fe(1)-O(5) bond length is 1.94 Å. The Fe(1)-O(6) bond length is 1.94 Å. Both Fe(1)-O(1) bond lengths are 2.06 Å. In the second Fe site, Fe(2) is bonded to one O(2), one O(4), one O(6), and two equivalent O(1) atoms to form FeO5 square pyramids that share corners with four equivalent Fe(1)O6 octahedra and  a cornercorner with one Fe(2)O5 square pyramid. The corner-sharing octahedral tilt angles range from 2-14°. The Fe(2)-O(2) bond length is 1.97 Å. The Fe(2)-O(4) bond length is 1.99 Å. The Fe(2)-O(6) bond length is 1.88 Å. Both Fe(2)-O(1) bond lengths are 1.90 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded to four equivalent Sr(1) and two equivalent Fe(2) atoms to form a mixture of distorted corner and edge-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 11-60°. In the third O site, O(3) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form a mixture of distorted face, corner, and edge-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles are 4°. In the fourth O site, O(4) is bonded to four equivalent Sr(1), one Fe(1), and one Fe(2) atom to form a mixture of distorted face, corner, and edge-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 4-60°. In the fifth O site, O(5) is bonded in a distorted linear geometry to four equivalent Sr(1) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded in a distorted linear geometry to four equivalent Sr(1), one Fe(1), and one Fe(2) atom.