Sr3MgCo2S2O5 crystallizes in the tetragonal I-4m2 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) 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 Co(1)O5 square pyramids. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to four equivalent S(1), two equivalent O(1), and two equivalent O(2) atoms. In the third Sr site, Sr(2) is bonded in a 8-coordinate geometry to four equivalent S(1), two equivalent O(1), and two equivalent O(2) atoms. Mg(1) is bonded to four equivalent S(1) atoms to form corner-sharing MgS4 tetrahedra. Co(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form CoO5 square pyramids that share corners with five equivalent Co(1)O5 square pyramids and faces with four equivalent Sr(1)O12 cuboctahedra. S(1) is bonded in a 6-coordinate geometry to four equivalent Sr(2) and two equivalent Mg(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Co(1) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Co(1) atoms. In the third O site, O(3) is bonded to four equivalent Sr(1) and two equivalent Co(1) atoms to form a mixture of distorted corner and edge-sharing OSr4Co2 octahedra. The corner-sharing octahedra are not tilted.
Sr3MgCo2S2O5 crystallizes in the tetragonal I-4m2 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) 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 Co(1)O5 square pyramids. All Sr(1)-O(1) bond lengths are 2.90 Å. All Sr(1)-O(2) bond lengths are 2.92 Å. All Sr(1)-O(3) bond lengths are 2.74 Å. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to four equivalent S(1), two equivalent O(1), and two equivalent O(2) atoms. All Sr(2)-S(1) bond lengths are 3.16 Å. Both Sr(2)-O(1) bond lengths are 2.56 Å. Both Sr(2)-O(2) bond lengths are 2.55 Å. In the third Sr site, Sr(2) is bonded in a 8-coordinate geometry to four equivalent S(1), two equivalent O(1), and two equivalent O(2) atoms. All Sr(2)-S(1) bond lengths are 3.16 Å. Both Sr(2)-O(1) bond lengths are 2.56 Å. Both Sr(2)-O(2) bond lengths are 2.55 Å. Mg(1) is bonded to four equivalent S(1) atoms to form corner-sharing MgS4 tetrahedra. All Mg(1)-S(1) bond lengths are 2.50 Å. Co(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form CoO5 square pyramids that share corners with five equivalent Co(1)O5 square pyramids and faces with four equivalent Sr(1)O12 cuboctahedra. The Co(1)-O(3) bond length is 1.94 Å. Both Co(1)-O(1) bond lengths are 1.95 Å. Both Co(1)-O(2) bond lengths are 1.95 Å. S(1) is bonded in a 6-coordinate geometry to four equivalent Sr(2) and two equivalent Mg(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Co(1) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Co(1) atoms. In the third O site, O(3) is bonded to four equivalent Sr(1) and two equivalent Co(1) atoms to form a mixture of distorted corner and edge-sharing OSr4Co2 octahedra. The corner-sharing octahedra are not tilted.