Sr4Fe4O11 crystallizes in the orthorhombic Cmmm space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted q6 geometry to one O(2), two equivalent O(3), and eight equivalent O(1) atoms. In the second Sr site, Sr(2) is bonded in a 10-coordinate geometry to two equivalent O(3) and eight equivalent O(1) atoms. In the third Sr site, Sr(3) is bonded to two equivalent O(2), two equivalent O(3), and eight equivalent O(1) atoms to form SrO12 cuboctahedra that share corners with two equivalent Sr(3)O12 cuboctahedra, faces with four equivalent Fe(1)O6 octahedra, and faces with four equivalent Fe(2)O5 square pyramids. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(2)O5 square pyramids, and faces with two equivalent Sr(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 13°. In the second Fe site, Fe(2) is bonded to one O(2) and four equivalent O(1) atoms to form FeO5 square pyramids that share corners with four equivalent Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O5 square pyramid, and faces with two equivalent Sr(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 12°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Sr(2), one Sr(3), two equivalent Sr(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded to two equivalent Sr(1), two equivalent Sr(3), and two equivalent Fe(2) atoms to form distorted corner-sharing OSr4Fe2 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Sr(2), one Sr(3), two equivalent Sr(1), and two equivalent Fe(1) atoms.
Sr4Fe4O11 crystallizes in the orthorhombic Cmmm space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted q6 geometry to one O(2), two equivalent O(3), and eight equivalent O(1) atoms. The Sr(1)-O(2) bond length is 2.63 Å. Both Sr(1)-O(3) bond lengths are 2.73 Å. There are four shorter (2.65 Å) and four longer (2.80 Å) Sr(1)-O(1) bond lengths. In the second Sr site, Sr(2) is bonded in a 10-coordinate geometry to two equivalent O(3) and eight equivalent O(1) atoms. Both Sr(2)-O(3) bond lengths are 2.95 Å. All Sr(2)-O(1) bond lengths are 2.60 Å. In the third Sr site, Sr(3) is bonded to two equivalent O(2), two equivalent O(3), and eight equivalent O(1) atoms to form SrO12 cuboctahedra that share corners with two equivalent Sr(3)O12 cuboctahedra, faces with four equivalent Fe(1)O6 octahedra, and faces with four equivalent Fe(2)O5 square pyramids. Both Sr(3)-O(2) bond lengths are 2.73 Å. Both Sr(3)-O(3) bond lengths are 2.53 Å. All Sr(3)-O(1) bond lengths are 2.87 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(2)O5 square pyramids, and faces with two equivalent Sr(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 13°. Both Fe(1)-O(3) bond lengths are 1.93 Å. All Fe(1)-O(1) bond lengths are 2.02 Å. In the second Fe site, Fe(2) is bonded to one O(2) and four equivalent O(1) atoms to form FeO5 square pyramids that share corners with four equivalent Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O5 square pyramid, and faces with two equivalent Sr(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 12°. The Fe(2)-O(2) bond length is 1.91 Å. All Fe(2)-O(1) bond lengths are 1.87 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Sr(2), one Sr(3), two equivalent Sr(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded to two equivalent Sr(1), two equivalent Sr(3), and two equivalent Fe(2) atoms to form distorted corner-sharing OSr4Fe2 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Sr(2), one Sr(3), two equivalent Sr(1), and two equivalent Fe(1) atoms.