Sr3Fe2S2O5 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Sr(1)O12 cuboctahedra, and faces with eight equivalent Fe(1)SO5 octahedra. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to five equivalent S(1) and four equivalent O(1) atoms. Fe(1) is bonded to one S(1), one O(2), and four equivalent O(1) atoms to form distorted FeSO5 octahedra that share corners with five equivalent Fe(1)SO5 octahedra and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. S(1) is bonded in a 6-coordinate geometry to five equivalent Sr(2) and one Fe(1) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(1) atoms to form a mixture of distorted edge, corner, and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Sr(1) and two equivalent Fe(1) atoms.
Sr3Fe2S2O5 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Sr(1)O12 cuboctahedra, and faces with eight equivalent Fe(1)SO5 octahedra. All Sr(1)-O(2) bond lengths are 2.84 Å. All Sr(1)-O(1) bond lengths are 2.81 Å. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to five equivalent S(1) and four equivalent O(1) atoms. There are four shorter (2.94 Å) and one longer (3.48 Å) Sr(2)-S(1) bond length. All Sr(2)-O(1) bond lengths are 2.65 Å. Fe(1) is bonded to one S(1), one O(2), and four equivalent O(1) atoms to form distorted FeSO5 octahedra that share corners with five equivalent Fe(1)SO5 octahedra and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. The Fe(1)-S(1) bond length is 2.53 Å. The Fe(1)-O(2) bond length is 1.92 Å. All Fe(1)-O(1) bond lengths are 2.01 Å. S(1) is bonded in a 6-coordinate geometry to five equivalent Sr(2) and one Fe(1) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(1) atoms to form a mixture of distorted edge, corner, and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Sr(1) and two equivalent Fe(1) atoms.