Ba4Nb14O23 crystallizes in the orthorhombic Cmmm space group. Ba(1) is bonded to one O(2), one O(5), one O(7), one O(9), two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form BaO12 cuboctahedra that share corners with five equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Nb(2)O5 square pyramids, faces with four equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(2)O5 square pyramids, faces with two equivalent Nb(3)O5 square pyramids, and faces with two equivalent Nb(4)O5 square pyramids. There are seven inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(3)O5 square pyramids, corners with two equivalent Nb(4)O5 square pyramids, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Nb site, Nb(2) is bonded to one O(6), two equivalent O(4), and two equivalent O(5) atoms to form NbO5 square pyramids that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one Nb(3)O5 square pyramid, corners with two equivalent Nb(2)O5 square pyramids, corners with two equivalent Nb(4)O5 square pyramids,  an edgeedge with one Nb(2)O5 square pyramid, and faces with two equivalent Ba(1)O12 cuboctahedra. In the third Nb site, Nb(3) is bonded to one O(1), two equivalent O(6), and two equivalent O(7) atoms to form NbO5 square pyramids that share  a cornercorner with one Nb(1)O6 octahedra, corners with two equivalent Nb(2)O5 square pyramids, corners with two equivalent Nb(3)O5 square pyramids, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the fourth Nb site, Nb(4) is bonded to one O(3), two equivalent O(4), and two equivalent O(9) atoms to form NbO5 square pyramids that share  a cornercorner with one Nb(1)O6 octahedra, corners with two equivalent Nb(4)O5 square pyramids, corners with four equivalent Nb(2)O5 square pyramids, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the fifth Nb site, Nb(5) is bonded in a square co-planar geometry to one O(8), one O(9), and two equivalent O(5) atoms. In the sixth Nb site, Nb(6) is bonded in a rectangular see-saw-like geometry to two equivalent O(6) and two equivalent O(8) atoms. In the seventh Nb site, Nb(7) is bonded in a square co-planar geometry to two equivalent O(7) and two equivalent O(8) atoms. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to four equivalent Ba(1), one Nb(1), and one Nb(3) atom. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Ba(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted linear geometry to four equivalent Ba(1), one Nb(1), and one Nb(4) atom. In the fourth O site, O(4) is bonded to two equivalent Ba(1), one Nb(4), and two equivalent Nb(2) atoms to form a mixture of distorted corner, edge, and face-sharing OBa2Nb3 trigonal bipyramids. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Nb(5), and two equivalent Nb(2) atoms. In the sixth O site, O(6) is bonded to two equivalent Ba(1), one Nb(2), one Nb(3), and one Nb(6) atom to form a mixture of distorted corner, edge, and face-sharing OBa2Nb3 trigonal bipyramids. In the seventh O site, O(7) is bonded to two equivalent Ba(1), one Nb(7), and two equivalent Nb(3) atoms to form a mixture of distorted corner and edge-sharing OBa2Nb3 trigonal bipyramids. In the eighth O site, O(8) is bonded in a square co-planar geometry to one Nb(5), one Nb(7), and two equivalent Nb(6) atoms. In the ninth O site, O(9) is bonded to two equivalent Ba(1), one Nb(5), and two equivalent Nb(4) atoms to form a mixture of distorted corner and edge-sharing OBa2Nb3 trigonal bipyramids.
Ba4Nb14O23 crystallizes in the orthorhombic Cmmm space group. Ba(1) is bonded to one O(2), one O(5), one O(7), one O(9), two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form BaO12 cuboctahedra that share corners with five equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Nb(2)O5 square pyramids, faces with four equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(2)O5 square pyramids, faces with two equivalent Nb(3)O5 square pyramids, and faces with two equivalent Nb(4)O5 square pyramids. The Ba(1)-O(2) bond length is 3.02 Å. The Ba(1)-O(5) bond length is 2.85 Å. The Ba(1)-O(7) bond length is 2.94 Å. The Ba(1)-O(9) bond length is 2.90 Å. Both Ba(1)-O(1) bond lengths are 3.00 Å. Both Ba(1)-O(3) bond lengths are 2.99 Å. Both Ba(1)-O(4) bond lengths are 2.91 Å. Both Ba(1)-O(6) bond lengths are 2.91 Å. There are seven inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(3)O5 square pyramids, corners with two equivalent Nb(4)O5 square pyramids, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. Both Nb(1)-O(1) bond lengths are 2.03 Å. Both Nb(1)-O(2) bond lengths are 2.09 Å. Both Nb(1)-O(3) bond lengths are 2.01 Å. In the second Nb site, Nb(2) is bonded to one O(6), two equivalent O(4), and two equivalent O(5) atoms to form NbO5 square pyramids that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one Nb(3)O5 square pyramid, corners with two equivalent Nb(2)O5 square pyramids, corners with two equivalent Nb(4)O5 square pyramids,  an edgeedge with one Nb(2)O5 square pyramid, and faces with two equivalent Ba(1)O12 cuboctahedra. The Nb(2)-O(6) bond length is 2.14 Å. There is one shorter (2.11 Å) and one longer (2.19 Å) Nb(2)-O(4) bond length. Both Nb(2)-O(5) bond lengths are 2.10 Å. In the third Nb site, Nb(3) is bonded to one O(1), two equivalent O(6), and two equivalent O(7) atoms to form NbO5 square pyramids that share  a cornercorner with one Nb(1)O6 octahedra, corners with two equivalent Nb(2)O5 square pyramids, corners with two equivalent Nb(3)O5 square pyramids, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. The Nb(3)-O(1) bond length is 2.20 Å. Both Nb(3)-O(6) bond lengths are 2.09 Å. Both Nb(3)-O(7) bond lengths are 2.10 Å. In the fourth Nb site, Nb(4) is bonded to one O(3), two equivalent O(4), and two equivalent O(9) atoms to form NbO5 square pyramids that share  a cornercorner with one Nb(1)O6 octahedra, corners with two equivalent Nb(4)O5 square pyramids, corners with four equivalent Nb(2)O5 square pyramids, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. The Nb(4)-O(3) bond length is 2.24 Å. Both Nb(4)-O(4) bond lengths are 2.10 Å. Both Nb(4)-O(9) bond lengths are 2.10 Å. In the fifth Nb site, Nb(5) is bonded in a square co-planar geometry to one O(8), one O(9), and two equivalent O(5) atoms. The Nb(5)-O(8) bond length is 2.17 Å. The Nb(5)-O(9) bond length is 2.11 Å. Both Nb(5)-O(5) bond lengths are 2.10 Å. In the sixth Nb site, Nb(6) is bonded in a rectangular see-saw-like geometry to two equivalent O(6) and two equivalent O(8) atoms. Both Nb(6)-O(6) bond lengths are 2.14 Å. Both Nb(6)-O(8) bond lengths are 2.09 Å. In the seventh Nb site, Nb(7) is bonded in a square co-planar geometry to two equivalent O(7) and two equivalent O(8) atoms. Both Nb(7)-O(7) bond lengths are 2.15 Å. Both Nb(7)-O(8) bond lengths are 2.10 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to four equivalent Ba(1), one Nb(1), and one Nb(3) atom. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Ba(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted linear geometry to four equivalent Ba(1), one Nb(1), and one Nb(4) atom. In the fourth O site, O(4) is bonded to two equivalent Ba(1), one Nb(4), and two equivalent Nb(2) atoms to form a mixture of distorted corner, edge, and face-sharing OBa2Nb3 trigonal bipyramids. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Nb(5), and two equivalent Nb(2) atoms. In the sixth O site, O(6) is bonded to two equivalent Ba(1), one Nb(2), one Nb(3), and one Nb(6) atom to form a mixture of distorted corner, edge, and face-sharing OBa2Nb3 trigonal bipyramids. In the seventh O site, O(7) is bonded to two equivalent Ba(1), one Nb(7), and two equivalent Nb(3) atoms to form a mixture of distorted corner and edge-sharing OBa2Nb3 trigonal bipyramids. In the eighth O site, O(8) is bonded in a square co-planar geometry to one Nb(5), one Nb(7), and two equivalent Nb(6) atoms. In the ninth O site, O(9) is bonded to two equivalent Ba(1), one Nb(5), and two equivalent Nb(4) atoms to form a mixture of distorted corner and edge-sharing OBa2Nb3 trigonal bipyramids.