Sr2Co2O5 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(10), one O(3), one O(5), one O(6), one O(8), two equivalent O(1), and two equivalent O(7) atoms. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(10), one O(3), one O(5), one O(6), one O(8), two equivalent O(2), and two equivalent O(4) atoms. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(10), one O(5), one O(6), one O(8), one O(9), two equivalent O(1), and two equivalent O(7) atoms. In the fourth Sr site, Sr(4) is bonded in a 9-coordinate geometry to one O(10), one O(5), one O(6), one O(8), one O(9), two equivalent O(2), and two equivalent O(4) atoms. 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 CoO4 tetrahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, and corners with two equivalent Co(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-26°. 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 corners with four equivalent Co(4)O6 octahedra,  a cornercorner with one Co(1)O4 tetrahedra, and  a cornercorner with one Co(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 4-5°. 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,  a cornercorner with one Co(4)O6 octahedra, and corners with two equivalent Co(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-26°. In the fourth Co site, Co(4) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(8) atom to form CoO6 octahedra that share corners with four equivalent Co(2)O6 octahedra,  a cornercorner with one Co(1)O4 tetrahedra, and  a cornercorner with one Co(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 4-5°. There are ten 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(3), one Co(1), and one Co(4) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(2), two equivalent Sr(4), one Co(3), and one Co(4) atom. In the third O site, O(3) is bonded to one Sr(1), one Sr(2), one Co(1), and one Co(3) atom to form distorted OSr2Co2 tetrahedra 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 two equivalent O(9)Sr2Co2 tetrahedra. The corner-sharing octahedral tilt angles range from 23-72°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(2), two equivalent Sr(4), 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)Sr2Co2 tetrahedra, corners with two equivalent O(9)Sr2Co2 tetrahedra, 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 are 1°. 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)Sr2Co2 tetrahedra, corners with two equivalent O(9)Sr2Co2 tetrahedra, 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)Sr2Co2 tetrahedra, corners with two equivalent O(9)Sr2Co2 tetrahedra, 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 Co(1), and one Co(3) atom to form distorted OSr2Co2 tetrahedra 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 two equivalent O(3)Sr2Co2 tetrahedra. The corner-sharing octahedral tilt angles range from 22-72°. 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)Sr2Co2 tetrahedra, corners with two equivalent O(9)Sr2Co2 tetrahedra, 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 are 1°.
Sr2Co2O5 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(10), one O(3), one O(5), one O(6), one O(8), two equivalent O(1), and two equivalent O(7) atoms. The Sr(1)-O(10) bond length is 2.66 Å. The Sr(1)-O(3) bond length is 2.43 Å. The Sr(1)-O(5) bond length is 2.68 Å. The Sr(1)-O(6) bond length is 2.65 Å. The Sr(1)-O(8) bond length is 2.63 Å. There is one shorter (2.56 Å) and one longer (3.11 Å) Sr(1)-O(1) bond length. There is one shorter (2.69 Å) and one longer (2.83 Å) Sr(1)-O(7) bond length. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(10), one O(3), one O(5), one O(6), one O(8), two equivalent O(2), and two equivalent O(4) atoms. The Sr(2)-O(10) bond length is 2.69 Å. The Sr(2)-O(3) bond length is 2.43 Å. The Sr(2)-O(5) bond length is 2.66 Å. The Sr(2)-O(6) bond length is 2.60 Å. The Sr(2)-O(8) bond length is 2.66 Å. There is one shorter (2.67 Å) and one longer (2.87 Å) Sr(2)-O(2) bond length. There is one shorter (2.58 Å) and one longer (3.06 Å) Sr(2)-O(4) bond length. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(10), one O(5), one O(6), one O(8), one O(9), two equivalent O(1), and two equivalent O(7) atoms. The Sr(3)-O(10) bond length is 2.66 Å. The Sr(3)-O(5) bond length is 2.69 Å. The Sr(3)-O(6) bond length is 2.66 Å. The Sr(3)-O(8) bond length is 2.59 Å. The Sr(3)-O(9) bond length is 2.43 Å. There is one shorter (2.70 Å) and one longer (2.85 Å) Sr(3)-O(1) bond length. There is one shorter (2.59 Å) and one longer (3.05 Å) Sr(3)-O(7) bond length. In the fourth Sr site, Sr(4) is bonded in a 9-coordinate geometry to one O(10), one O(5), one O(6), one O(8), one O(9), two equivalent O(2), and two equivalent O(4) atoms. The Sr(4)-O(10) bond length is 2.67 Å. The Sr(4)-O(5) bond length is 2.66 Å. The Sr(4)-O(6) bond length is 2.62 Å. The Sr(4)-O(8) bond length is 2.66 Å. The Sr(4)-O(9) bond length is 2.43 Å. There is one shorter (2.57 Å) and one longer (3.11 Å) Sr(4)-O(2) bond length. There is one shorter (2.69 Å) and one longer (2.83 Å) Sr(4)-O(4) bond length. 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 CoO4 tetrahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, and corners with two equivalent Co(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-26°. The Co(1)-O(1) bond length is 1.82 Å. The Co(1)-O(3) bond length is 1.93 Å. The Co(1)-O(4) bond length is 1.85 Å. The Co(1)-O(9) bond length is 1.95 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 corners with four equivalent Co(4)O6 octahedra,  a cornercorner with one Co(1)O4 tetrahedra, and  a cornercorner with one Co(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 4-5°. The Co(2)-O(10) bond length is 1.86 Å. The Co(2)-O(4) bond length is 2.29 Å. The Co(2)-O(5) bond length is 1.86 Å. The Co(2)-O(6) bond length is 2.04 Å. The Co(2)-O(7) bond length is 2.27 Å. The Co(2)-O(8) bond length is 2.04 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,  a cornercorner with one Co(4)O6 octahedra, and corners with two equivalent Co(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-26°. The Co(3)-O(2) bond length is 1.82 Å. The Co(3)-O(3) bond length is 1.94 Å. The Co(3)-O(7) bond length is 1.85 Å. The Co(3)-O(9) bond length is 1.94 Å. In the fourth Co site, Co(4) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(8) atom to form CoO6 octahedra that share corners with four equivalent Co(2)O6 octahedra,  a cornercorner with one Co(1)O4 tetrahedra, and  a cornercorner with one Co(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 4-5°. The Co(4)-O(1) bond length is 2.38 Å. The Co(4)-O(10) bond length is 1.98 Å. The Co(4)-O(2) bond length is 2.35 Å. The Co(4)-O(5) bond length is 1.98 Å. The Co(4)-O(6) bond length is 1.90 Å. The Co(4)-O(8) bond length is 1.90 Å. There are ten 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(3), one Co(1), and one Co(4) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(2), two equivalent Sr(4), one Co(3), and one Co(4) atom. In the third O site, O(3) is bonded to one Sr(1), one Sr(2), one Co(1), and one Co(3) atom to form distorted OSr2Co2 tetrahedra 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 two equivalent O(9)Sr2Co2 tetrahedra. The corner-sharing octahedral tilt angles range from 23-72°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(2), two equivalent Sr(4), 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)Sr2Co2 tetrahedra, corners with two equivalent O(9)Sr2Co2 tetrahedra, 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 are 1°. 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)Sr2Co2 tetrahedra, corners with two equivalent O(9)Sr2Co2 tetrahedra, 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)Sr2Co2 tetrahedra, corners with two equivalent O(9)Sr2Co2 tetrahedra, 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 Co(1), and one Co(3) atom to form distorted OSr2Co2 tetrahedra 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 two equivalent O(3)Sr2Co2 tetrahedra. The corner-sharing octahedral tilt angles range from 22-72°. 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)Sr2Co2 tetrahedra, corners with two equivalent O(9)Sr2Co2 tetrahedra, 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 are 1°.