Ba7Sr(CuO3)8 is (Cubic) Perovskite-derived structured and crystallizes in the cubic Pm-3m space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, corners with eight equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra, and faces with eight equivalent Cu(1)O6 octahedra. In the second Ba site, Ba(2) is bonded to four equivalent O(1) and eight equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(3)O12 cuboctahedra, corners with eight equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with eight equivalent Cu(1)O6 octahedra. In the third Ba site, Ba(3) is bonded to twelve equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(2)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra, and faces with eight equivalent Cu(1)O6 octahedra. Sr(1) is bonded to twelve equivalent O(2) atoms to form SrO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, faces with six equivalent Ba(2)O12 cuboctahedra, and faces with eight equivalent Cu(1)O6 octahedra. Cu(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form CuO6 octahedra that share corners with six equivalent Cu(1)O6 octahedra,  a faceface with one Ba(3)O12 cuboctahedra,  a faceface with one Sr(1)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and faces with three equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Ba(2), one Ba(3), two equivalent Ba(1), and two equivalent Cu(1) atoms to form distorted OBa4Cu2 octahedra that share corners with ten equivalent O(2)Ba3SrCu2 octahedra, corners with twelve equivalent O(1)Ba4Cu2 octahedra, edges with four equivalent O(1)Ba4Cu2 octahedra, faces with four equivalent O(2)Ba3SrCu2 octahedra, and faces with four equivalent O(1)Ba4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the second O site, O(2) is bonded to one Ba(1), two equivalent Ba(2), one Sr(1), and two equivalent Cu(1) atoms to form distorted OBa3SrCu2 octahedra that share corners with ten equivalent O(1)Ba4Cu2 octahedra, corners with twelve equivalent O(2)Ba3SrCu2 octahedra, edges with four equivalent O(2)Ba3SrCu2 octahedra, faces with four equivalent O(2)Ba3SrCu2 octahedra, and faces with four equivalent O(1)Ba4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°.
Ba7Sr(CuO3)8 is (Cubic) Perovskite-derived structured and crystallizes in the cubic Pm-3m space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, corners with eight equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra, and faces with eight equivalent Cu(1)O6 octahedra. All Ba(1)-O(2) bond lengths are 2.89 Å. All Ba(1)-O(1) bond lengths are 2.83 Å. In the second Ba site, Ba(2) is bonded to four equivalent O(1) and eight equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(3)O12 cuboctahedra, corners with eight equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with eight equivalent Cu(1)O6 octahedra. All Ba(2)-O(1) bond lengths are 2.82 Å. All Ba(2)-O(2) bond lengths are 2.83 Å. In the third Ba site, Ba(3) is bonded to twelve equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(2)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra, and faces with eight equivalent Cu(1)O6 octahedra. All Ba(3)-O(1) bond lengths are 2.83 Å. Sr(1) is bonded to twelve equivalent O(2) atoms to form SrO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, faces with six equivalent Ba(2)O12 cuboctahedra, and faces with eight equivalent Cu(1)O6 octahedra. All Sr(1)-O(2) bond lengths are 2.77 Å. Cu(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form CuO6 octahedra that share corners with six equivalent Cu(1)O6 octahedra,  a faceface with one Ba(3)O12 cuboctahedra,  a faceface with one Sr(1)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and faces with three equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. All Cu(1)-O(1) bond lengths are 2.00 Å. All Cu(1)-O(2) bond lengths are 2.00 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Ba(2), one Ba(3), two equivalent Ba(1), and two equivalent Cu(1) atoms to form distorted OBa4Cu2 octahedra that share corners with ten equivalent O(2)Ba3SrCu2 octahedra, corners with twelve equivalent O(1)Ba4Cu2 octahedra, edges with four equivalent O(1)Ba4Cu2 octahedra, faces with four equivalent O(2)Ba3SrCu2 octahedra, and faces with four equivalent O(1)Ba4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the second O site, O(2) is bonded to one Ba(1), two equivalent Ba(2), one Sr(1), and two equivalent Cu(1) atoms to form distorted OBa3SrCu2 octahedra that share corners with ten equivalent O(1)Ba4Cu2 octahedra, corners with twelve equivalent O(2)Ba3SrCu2 octahedra, edges with four equivalent O(2)Ba3SrCu2 octahedra, faces with four equivalent O(2)Ba3SrCu2 octahedra, and faces with four equivalent O(1)Ba4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°.