Ba6Bi6O17 crystallizes in the orthorhombic Immm space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to two equivalent O(2), two equivalent O(3), and eight equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(3)O12 cuboctahedra, faces with four equivalent Bi(2)O6 octahedra, and faces with four equivalent Bi(1)O5 square pyramids. In the second Ba site, Ba(2) is bonded in a distorted q6 geometry to one O(2), two equivalent O(4), four equivalent O(1), and four equivalent O(5) atoms. In the third Ba site, Ba(3) is bonded to one O(3), one O(4), two equivalent O(2), four equivalent O(1), and four equivalent O(5) atoms to form BaO12 cuboctahedra that share corners with seven equivalent Ba(3)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with six equivalent Bi(2)O6 octahedra, and faces with two equivalent Bi(1)O5 square pyramids. In the fourth Ba site, Ba(4) is bonded in a distorted q6 geometry to two equivalent O(4) and eight equivalent O(1) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(3) and four equivalent O(1) atoms to form BiO5 square pyramids that share corners with four equivalent Bi(2)O6 octahedra,  a cornercorner with one Bi(1)O5 square pyramid, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with two equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 2°. In the second Bi site, Bi(2) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(5) atoms to form BiO6 octahedra that share corners with four equivalent Bi(2)O6 octahedra, corners with two equivalent Bi(1)O5 square pyramids,  a faceface with one Ba(1)O12 cuboctahedra, and faces with three equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(4), one Bi(1), and one Bi(2) atom to form a mixture of distorted face, corner, and edge-sharing OBa4Bi2 octahedra. The corner-sharing octahedral tilt angles range from 0-68°. In the second O site, O(2) is bonded to one Ba(1), one Ba(2), two equivalent Ba(3), and two equivalent Bi(2) atoms to form a mixture of distorted face and corner-sharing OBa4Bi2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(3), and two equivalent Bi(1) atoms. In the fourth O site, O(4) is bonded in a distorted linear geometry to one Ba(3), one Ba(4), two equivalent Ba(2), and two equivalent Bi(2) atoms. In the fifth O site, O(5) is bonded to two equivalent Ba(2), two equivalent Ba(3), and two equivalent Bi(2) atoms to form a mixture of distorted face, corner, and edge-sharing OBa4Bi2 octahedra. The corner-sharing octahedral tilt angles range from 1-62°.
Ba6Bi6O17 crystallizes in the orthorhombic Immm space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to two equivalent O(2), two equivalent O(3), and eight equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(3)O12 cuboctahedra, faces with four equivalent Bi(2)O6 octahedra, and faces with four equivalent Bi(1)O5 square pyramids. Both Ba(1)-O(2) bond lengths are 3.19 Å. Both Ba(1)-O(3) bond lengths are 3.17 Å. All Ba(1)-O(1) bond lengths are 3.15 Å. In the second Ba site, Ba(2) is bonded in a distorted q6 geometry to one O(2), two equivalent O(4), four equivalent O(1), and four equivalent O(5) atoms. The Ba(2)-O(2) bond length is 2.95 Å. Both Ba(2)-O(4) bond lengths are 3.17 Å. All Ba(2)-O(1) bond lengths are 3.21 Å. All Ba(2)-O(5) bond lengths are 3.02 Å. In the third Ba site, Ba(3) is bonded to one O(3), one O(4), two equivalent O(2), four equivalent O(1), and four equivalent O(5) atoms to form BaO12 cuboctahedra that share corners with seven equivalent Ba(3)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with six equivalent Bi(2)O6 octahedra, and faces with two equivalent Bi(1)O5 square pyramids. The Ba(3)-O(3) bond length is 3.20 Å. The Ba(3)-O(4) bond length is 3.13 Å. Both Ba(3)-O(2) bond lengths are 3.17 Å. All Ba(3)-O(1) bond lengths are 3.18 Å. All Ba(3)-O(5) bond lengths are 3.11 Å. In the fourth Ba site, Ba(4) is bonded in a distorted q6 geometry to two equivalent O(4) and eight equivalent O(1) atoms. Both Ba(4)-O(4) bond lengths are 3.19 Å. All Ba(4)-O(1) bond lengths are 3.07 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(3) and four equivalent O(1) atoms to form BiO5 square pyramids that share corners with four equivalent Bi(2)O6 octahedra,  a cornercorner with one Bi(1)O5 square pyramid, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with two equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 2°. The Bi(1)-O(3) bond length is 2.19 Å. All Bi(1)-O(1) bond lengths are 2.25 Å. In the second Bi site, Bi(2) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(5) atoms to form BiO6 octahedra that share corners with four equivalent Bi(2)O6 octahedra, corners with two equivalent Bi(1)O5 square pyramids,  a faceface with one Ba(1)O12 cuboctahedra, and faces with three equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. The Bi(2)-O(2) bond length is 2.19 Å. The Bi(2)-O(4) bond length is 2.16 Å. Both Bi(2)-O(1) bond lengths are 2.22 Å. Both Bi(2)-O(5) bond lengths are 2.25 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(4), one Bi(1), and one Bi(2) atom to form a mixture of distorted face, corner, and edge-sharing OBa4Bi2 octahedra. The corner-sharing octahedral tilt angles range from 0-68°. In the second O site, O(2) is bonded to one Ba(1), one Ba(2), two equivalent Ba(3), and two equivalent Bi(2) atoms to form a mixture of distorted face and corner-sharing OBa4Bi2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(3), and two equivalent Bi(1) atoms. In the fourth O site, O(4) is bonded in a distorted linear geometry to one Ba(3), one Ba(4), two equivalent Ba(2), and two equivalent Bi(2) atoms. In the fifth O site, O(5) is bonded to two equivalent Ba(2), two equivalent Ba(3), and two equivalent Bi(2) atoms to form a mixture of distorted face, corner, and edge-sharing OBa4Bi2 octahedra. The corner-sharing octahedral tilt angles range from 1-62°.