Ba6CoNb9O30 crystallizes in the orthorhombic Cmm2 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(7), two equivalent O(3), and four equivalent O(2) atoms. In the second Ba site, Ba(2) is bonded in a 13-coordinate geometry to one O(8), two equivalent O(4), two equivalent O(5), four equivalent O(1), and four equivalent O(9) atoms. In the third Ba site, Ba(3) is bonded to two equivalent O(5), two equivalent O(6), four equivalent O(10), and four equivalent O(9) atoms to form BaO12 cuboctahedra that share faces with two equivalent Ba(3)O12 cuboctahedra, faces with four equivalent Nb(1)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(2), one O(4), one O(9), and two equivalent O(5) atoms to form NbO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with three equivalent Nb(1)O6 octahedra, and faces with two equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 6-45°. In the second Nb site, Nb(2) is bonded to one O(1), one O(10), one O(3), one O(9), and two equivalent O(6) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra, and faces with two equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 6-39°. In the third Nb site, Nb(3) is bonded to two equivalent O(8) and four equivalent O(1) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-34°. Co(1) is bonded to two equivalent O(7) and four equivalent O(2) atoms to form CoO6 octahedra that share corners with two equivalent Co(1)O6 octahedra and corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-34°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(2), one Nb(2), and one Nb(3) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(1), one Nb(1), and one Co(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ba(1) and two equivalent Nb(2) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ba(2) and two equivalent Nb(1) atoms. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ba(2), one Ba(3), and two equivalent Nb(1) atoms. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ba(3) and two equivalent Nb(2) atoms. In the seventh O site, O(7) is bonded in a distorted square co-planar geometry to two equivalent Ba(1) and two equivalent Co(1) atoms. In the eighth O site, O(8) is bonded in a distorted linear geometry to two equivalent Ba(2) and two equivalent Nb(3) atoms. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Ba(2), two equivalent Ba(3), one Nb(1), and one Nb(2) atom. In the tenth O site, O(10) is bonded in a distorted linear geometry to two equivalent Ba(3), one Nb(1), and one Nb(2) atom.
Ba6CoNb9O30 crystallizes in the orthorhombic Cmm2 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(7), two equivalent O(3), and four equivalent O(2) atoms. The Ba(1)-O(7) bond length is 2.83 Å. There is one shorter (3.01 Å) and one longer (3.07 Å) Ba(1)-O(3) bond length. There are two shorter (2.79 Å) and two longer (2.82 Å) Ba(1)-O(2) bond lengths. In the second Ba site, Ba(2) is bonded in a 13-coordinate geometry to one O(8), two equivalent O(4), two equivalent O(5), four equivalent O(1), and four equivalent O(9) atoms. The Ba(2)-O(8) bond length is 3.19 Å. There is one shorter (2.78 Å) and one longer (2.80 Å) Ba(2)-O(4) bond length. Both Ba(2)-O(5) bond lengths are 3.13 Å. There are two shorter (2.97 Å) and two longer (3.00 Å) Ba(2)-O(1) bond lengths. There are two shorter (3.38 Å) and two longer (3.39 Å) Ba(2)-O(9) bond lengths. In the third Ba site, Ba(3) is bonded to two equivalent O(5), two equivalent O(6), four equivalent O(10), and four equivalent O(9) atoms to form BaO12 cuboctahedra that share faces with two equivalent Ba(3)O12 cuboctahedra, faces with four equivalent Nb(1)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. Both Ba(3)-O(5) bond lengths are 2.83 Å. Both Ba(3)-O(6) bond lengths are 2.83 Å. There are two shorter (2.80 Å) and two longer (2.87 Å) Ba(3)-O(10) bond lengths. There are two shorter (2.82 Å) and two longer (2.89 Å) Ba(3)-O(9) bond lengths. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(2), one O(4), one O(9), and two equivalent O(5) atoms to form NbO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with three equivalent Nb(1)O6 octahedra, and faces with two equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 6-45°. The Nb(1)-O(10) bond length is 2.04 Å. The Nb(1)-O(2) bond length is 1.88 Å. The Nb(1)-O(4) bond length is 2.03 Å. The Nb(1)-O(9) bond length is 2.17 Å. There is one shorter (1.96 Å) and one longer (2.12 Å) Nb(1)-O(5) bond length. In the second Nb site, Nb(2) is bonded to one O(1), one O(10), one O(3), one O(9), and two equivalent O(6) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra, and faces with two equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 6-39°. The Nb(2)-O(1) bond length is 1.98 Å. The Nb(2)-O(10) bond length is 2.05 Å. The Nb(2)-O(3) bond length is 2.04 Å. The Nb(2)-O(9) bond length is 2.02 Å. There is one shorter (1.90 Å) and one longer (2.17 Å) Nb(2)-O(6) bond length. In the third Nb site, Nb(3) is bonded to two equivalent O(8) and four equivalent O(1) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-34°. There is one shorter (1.85 Å) and one longer (2.21 Å) Nb(3)-O(8) bond length. All Nb(3)-O(1) bond lengths are 2.00 Å. Co(1) is bonded to two equivalent O(7) and four equivalent O(2) atoms to form CoO6 octahedra that share corners with two equivalent Co(1)O6 octahedra and corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-34°. There is one shorter (2.02 Å) and one longer (2.03 Å) Co(1)-O(7) bond length. All Co(1)-O(2) bond lengths are 2.01 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(2), one Nb(2), and one Nb(3) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(1), one Nb(1), and one Co(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ba(1) and two equivalent Nb(2) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ba(2) and two equivalent Nb(1) atoms. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ba(2), one Ba(3), and two equivalent Nb(1) atoms. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ba(3) and two equivalent Nb(2) atoms. In the seventh O site, O(7) is bonded in a distorted square co-planar geometry to two equivalent Ba(1) and two equivalent Co(1) atoms. In the eighth O site, O(8) is bonded in a distorted linear geometry to two equivalent Ba(2) and two equivalent Nb(3) atoms. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Ba(2), two equivalent Ba(3), one Nb(1), and one Nb(2) atom. In the tenth O site, O(10) is bonded in a distorted linear geometry to two equivalent Ba(3), one Nb(1), and one Nb(2) atom.