Sr4Mg(Co2O5)2 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), one O(5), one O(6), one O(8), and two equivalent O(7) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(10), one O(2), one O(3), one O(5), one O(6), one O(8), and two equivalent O(4) atoms. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(5), one O(6), one O(8), one O(9), and two equivalent O(7) atoms. In the fourth Sr site, Sr(4) is bonded in a 8-coordinate geometry to one O(10), one O(2), one O(5), one O(6), one O(8), one O(9), and two equivalent O(4) atoms. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(9) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(3)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra,  an edgeedge with one Co(1)O4 tetrahedra, and  an edgeedge with one Co(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(3), one O(4), and one O(9) atom to form distorted CoO4 tetrahedra that share  a cornercorner with one Co(2)O6 octahedra, corners with two equivalent Co(3)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 32°. In the second Co site, Co(2) is bonded to one O(10), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form CoO6 octahedra that share  a cornercorner with one Co(1)O4 tetrahedra,  a cornercorner with one Co(3)O4 tetrahedra, and  a cornercorner with one Mg(1)O5 trigonal bipyramid. In the third Co site, Co(3) is bonded to one O(2), one O(3), one O(7), and one O(9) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(2)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 19°. In the fourth Co site, Co(4) is bonded in a rectangular see-saw-like geometry to one O(10), one O(5), one O(6), and one O(8) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Sr(1), one Sr(3), one Mg(1), and one Co(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Sr(2), one Sr(4), one Mg(1), and one Co(3) atom. In the third O site, O(3) is bonded to one Sr(1), one Sr(2), one Mg(1), one Co(1), and one Co(3) atom to form distorted OSr2MgCo2 square pyramids that share corners with two equivalent O(10)Sr4Co2 octahedra, corners with two equivalent O(5)Sr4Co2 octahedra, corners with two equivalent O(6)Sr4Co2 octahedra, corners with two equivalent O(8)Sr4Co2 octahedra, and corners with three equivalent O(9)Sr2MgCo2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 31-63°. In the fourth O site, O(4) is bonded in a 7-coordinate geometry to two equivalent Sr(2), two equivalent Sr(4), one Mg(1), one Co(1), and one Co(2) atom. In the fifth O site, O(5) is bonded to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Co(2), and one Co(4) atom to form distorted OSr4Co2 octahedra that share corners with two equivalent O(10)Sr4Co2 octahedra, corners with two equivalent O(3)Sr2MgCo2 square pyramids, corners with two equivalent O(9)Sr2MgCo2 trigonal bipyramids, edges with two equivalent O(10)Sr4Co2 octahedra, faces with two equivalent O(6)Sr4Co2 octahedra, and faces with two equivalent O(8)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-2°. In the sixth O site, O(6) is bonded to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Co(2), and one Co(4) atom to form distorted OSr4Co2 octahedra that share corners with two equivalent O(8)Sr4Co2 octahedra, corners with two equivalent O(3)Sr2MgCo2 square pyramids, corners with two equivalent O(9)Sr2MgCo2 trigonal bipyramids, edges with two equivalent O(8)Sr4Co2 octahedra, faces with two equivalent O(10)Sr4Co2 octahedra, and faces with two equivalent O(5)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(3), one Co(2), and one Co(3) atom. In the eighth O site, O(8) is bonded to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Co(2), and one Co(4) atom to form distorted OSr4Co2 octahedra that share corners with two equivalent O(6)Sr4Co2 octahedra, corners with two equivalent O(3)Sr2MgCo2 square pyramids, corners with two equivalent O(9)Sr2MgCo2 trigonal bipyramids, edges with two equivalent O(6)Sr4Co2 octahedra, faces with two equivalent O(10)Sr4Co2 octahedra, and faces with two equivalent O(5)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the ninth O site, O(9) is bonded to one Sr(3), one Sr(4), one Mg(1), one Co(1), and one Co(3) atom to form distorted OSr2MgCo2 trigonal bipyramids that share corners with two equivalent O(10)Sr4Co2 octahedra, corners with two equivalent O(5)Sr4Co2 octahedra, corners with two equivalent O(6)Sr4Co2 octahedra, corners with two equivalent O(8)Sr4Co2 octahedra, and corners with three equivalent O(3)Sr2MgCo2 square pyramids. The corner-sharing octahedral tilt angles range from 35-63°. In the tenth O site, O(10) is bonded to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Co(2), and one Co(4) atom to form distorted OSr4Co2 octahedra that share corners with two equivalent O(5)Sr4Co2 octahedra, corners with two equivalent O(3)Sr2MgCo2 square pyramids, corners with two equivalent O(9)Sr2MgCo2 trigonal bipyramids, edges with two equivalent O(5)Sr4Co2 octahedra, faces with two equivalent O(6)Sr4Co2 octahedra, and faces with two equivalent O(8)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-2°.
Sr4Mg(Co2O5)2 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), one O(5), one O(6), one O(8), and two equivalent O(7) atoms. The Sr(1)-O(1) bond length is 2.59 Å. The Sr(1)-O(10) bond length is 2.75 Å. The Sr(1)-O(3) bond length is 2.49 Å. The Sr(1)-O(5) bond length is 2.65 Å. The Sr(1)-O(6) bond length is 2.64 Å. The Sr(1)-O(8) bond length is 2.69 Å. There is one shorter (2.73 Å) and one longer (2.82 Å) Sr(1)-O(7) bond length. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(10), one O(2), one O(3), one O(5), one O(6), one O(8), and two equivalent O(4) atoms. The Sr(2)-O(10) bond length is 2.65 Å. The Sr(2)-O(2) bond length is 2.62 Å. The Sr(2)-O(3) bond length is 2.55 Å. The Sr(2)-O(5) bond length is 2.59 Å. The Sr(2)-O(6) bond length is 2.58 Å. The Sr(2)-O(8) bond length is 2.64 Å. There is one shorter (2.86 Å) and one longer (2.88 Å) Sr(2)-O(4) bond length. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(5), one O(6), one O(8), one O(9), and two equivalent O(7) atoms. The Sr(3)-O(1) bond length is 2.60 Å. The Sr(3)-O(10) bond length is 2.62 Å. The Sr(3)-O(5) bond length is 2.65 Å. The Sr(3)-O(6) bond length is 2.60 Å. The Sr(3)-O(8) bond length is 2.61 Å. The Sr(3)-O(9) bond length is 2.60 Å. There is one shorter (2.82 Å) and one longer (2.84 Å) Sr(3)-O(7) bond length. In the fourth Sr site, Sr(4) is bonded in a 8-coordinate geometry to one O(10), one O(2), one O(5), one O(6), one O(8), one O(9), and two equivalent O(4) atoms. The Sr(4)-O(10) bond length is 2.57 Å. The Sr(4)-O(2) bond length is 2.51 Å. The Sr(4)-O(5) bond length is 2.65 Å. The Sr(4)-O(6) bond length is 2.56 Å. The Sr(4)-O(8) bond length is 2.63 Å. The Sr(4)-O(9) bond length is 2.59 Å. There is one shorter (2.67 Å) and one longer (3.00 Å) Sr(4)-O(4) bond length. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(9) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(3)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra,  an edgeedge with one Co(1)O4 tetrahedra, and  an edgeedge with one Co(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. The Mg(1)-O(1) bond length is 2.03 Å. The Mg(1)-O(2) bond length is 2.15 Å. The Mg(1)-O(3) bond length is 2.21 Å. The Mg(1)-O(4) bond length is 2.04 Å. The Mg(1)-O(9) bond length is 2.17 Å. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(3), one O(4), and one O(9) atom to form distorted CoO4 tetrahedra that share  a cornercorner with one Co(2)O6 octahedra, corners with two equivalent Co(3)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 32°. The Co(1)-O(1) bond length is 1.95 Å. The Co(1)-O(3) bond length is 2.00 Å. The Co(1)-O(4) bond length is 2.10 Å. The Co(1)-O(9) bond length is 2.02 Å. In the second Co site, Co(2) is bonded to one O(10), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form CoO6 octahedra that share  a cornercorner with one Co(1)O4 tetrahedra,  a cornercorner with one Co(3)O4 tetrahedra, and  a cornercorner with one Mg(1)O5 trigonal bipyramid. The Co(2)-O(10) bond length is 1.99 Å. The Co(2)-O(4) bond length is 2.52 Å. The Co(2)-O(5) bond length is 2.01 Å. The Co(2)-O(6) bond length is 2.06 Å. The Co(2)-O(7) bond length is 2.33 Å. The Co(2)-O(8) bond length is 2.03 Å. In the third Co site, Co(3) is bonded to one O(2), one O(3), one O(7), and one O(9) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(2)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 19°. The Co(3)-O(2) bond length is 1.82 Å. The Co(3)-O(3) bond length is 2.01 Å. The Co(3)-O(7) bond length is 1.85 Å. The Co(3)-O(9) bond length is 1.91 Å. In the fourth Co site, Co(4) is bonded in a rectangular see-saw-like geometry to one O(10), one O(5), one O(6), and one O(8) atom. The Co(4)-O(10) bond length is 1.85 Å. The Co(4)-O(5) bond length is 1.86 Å. The Co(4)-O(6) bond length is 1.88 Å. The Co(4)-O(8) bond length is 1.86 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Sr(1), one Sr(3), one Mg(1), and one Co(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Sr(2), one Sr(4), one Mg(1), and one Co(3) atom. In the third O site, O(3) is bonded to one Sr(1), one Sr(2), one Mg(1), one Co(1), and one Co(3) atom to form distorted OSr2MgCo2 square pyramids that share corners with two equivalent O(10)Sr4Co2 octahedra, corners with two equivalent O(5)Sr4Co2 octahedra, corners with two equivalent O(6)Sr4Co2 octahedra, corners with two equivalent O(8)Sr4Co2 octahedra, and corners with three equivalent O(9)Sr2MgCo2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 31-63°. In the fourth O site, O(4) is bonded in a 7-coordinate geometry to two equivalent Sr(2), two equivalent Sr(4), one Mg(1), one Co(1), and one Co(2) atom. In the fifth O site, O(5) is bonded to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Co(2), and one Co(4) atom to form distorted OSr4Co2 octahedra that share corners with two equivalent O(10)Sr4Co2 octahedra, corners with two equivalent O(3)Sr2MgCo2 square pyramids, corners with two equivalent O(9)Sr2MgCo2 trigonal bipyramids, edges with two equivalent O(10)Sr4Co2 octahedra, faces with two equivalent O(6)Sr4Co2 octahedra, and faces with two equivalent O(8)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-2°. In the sixth O site, O(6) is bonded to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Co(2), and one Co(4) atom to form distorted OSr4Co2 octahedra that share corners with two equivalent O(8)Sr4Co2 octahedra, corners with two equivalent O(3)Sr2MgCo2 square pyramids, corners with two equivalent O(9)Sr2MgCo2 trigonal bipyramids, edges with two equivalent O(8)Sr4Co2 octahedra, faces with two equivalent O(10)Sr4Co2 octahedra, and faces with two equivalent O(5)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(3), one Co(2), and one Co(3) atom. In the eighth O site, O(8) is bonded to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Co(2), and one Co(4) atom to form distorted OSr4Co2 octahedra that share corners with two equivalent O(6)Sr4Co2 octahedra, corners with two equivalent O(3)Sr2MgCo2 square pyramids, corners with two equivalent O(9)Sr2MgCo2 trigonal bipyramids, edges with two equivalent O(6)Sr4Co2 octahedra, faces with two equivalent O(10)Sr4Co2 octahedra, and faces with two equivalent O(5)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the ninth O site, O(9) is bonded to one Sr(3), one Sr(4), one Mg(1), one Co(1), and one Co(3) atom to form distorted OSr2MgCo2 trigonal bipyramids that share corners with two equivalent O(10)Sr4Co2 octahedra, corners with two equivalent O(5)Sr4Co2 octahedra, corners with two equivalent O(6)Sr4Co2 octahedra, corners with two equivalent O(8)Sr4Co2 octahedra, and corners with three equivalent O(3)Sr2MgCo2 square pyramids. The corner-sharing octahedral tilt angles range from 35-63°. In the tenth O site, O(10) is bonded to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Co(2), and one Co(4) atom to form distorted OSr4Co2 octahedra that share corners with two equivalent O(5)Sr4Co2 octahedra, corners with two equivalent O(3)Sr2MgCo2 square pyramids, corners with two equivalent O(9)Sr2MgCo2 trigonal bipyramids, edges with two equivalent O(5)Sr4Co2 octahedra, faces with two equivalent O(6)Sr4Co2 octahedra, and faces with two equivalent O(8)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-2°.