Ba9Nb10O30 crystallizes in the triclinic P-1 space group. There are five inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(12), one O(14), one O(15), one O(2), one O(5), one O(7), one O(8), one O(9), two equivalent O(1), and two equivalent O(4) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(1)O12 cuboctahedra, corners with two equivalent Ba(2)O12 cuboctahedra, corners with two equivalent Ba(5)O12 cuboctahedra, corners with three equivalent Ba(3)O12 cuboctahedra, corners with three equivalent Ba(4)O12 cuboctahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(3)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra,  a faceface with one Nb(2)O6 octahedra,  a faceface with one Nb(4)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, and faces with two equivalent Nb(5)O6 octahedra. In the second Ba site, Ba(2) is bonded to one O(1), one O(10), one O(12), one O(14), one O(15), one O(3), one O(7), one O(9), two equivalent O(13), and two equivalent O(5) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(2)O12 cuboctahedra,  a cornercorner with one Ba(5)O12 cuboctahedra, corners with two equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ba(4)O12 cuboctahedra, corners with four equivalent Ba(3)O12 cuboctahedra,  a faceface with one Ba(2)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra,  a faceface with one Nb(1)O6 octahedra,  a faceface with one Nb(3)O6 octahedra, faces with two equivalent Nb(2)O6 octahedra, faces with two equivalent Nb(4)O6 octahedra, and faces with two equivalent Nb(5)O6 octahedra. In the third Ba site, Ba(3) is bonded to one O(10), one O(11), one O(14), one O(16), one O(2), one O(3), one O(4), one O(9), two equivalent O(6), and two equivalent O(8) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(3)O12 cuboctahedra,  a cornercorner with one Ba(5)O12 cuboctahedra, corners with two equivalent Ba(4)O12 cuboctahedra, corners with three equivalent Ba(1)O12 cuboctahedra, corners with four equivalent Ba(2)O12 cuboctahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(3)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(4)O12 cuboctahedra,  a faceface with one Nb(4)O6 octahedra,  a faceface with one Nb(5)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(2)O6 octahedra, and faces with two equivalent Nb(3)O6 octahedra. In the fourth Ba site, Ba(4) is bonded to one O(13), one O(14), one O(16), one O(2), one O(3), one O(4), one O(6), one O(7), two equivalent O(11), and two equivalent O(15) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(4)O12 cuboctahedra,  a cornercorner with one Ba(5)O12 cuboctahedra, corners with two equivalent Ba(3)O12 cuboctahedra, corners with three equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ba(2)O12 cuboctahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(2)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra,  a faceface with one Nb(2)O6 octahedra,  a faceface with one Nb(3)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(4)O6 octahedra, and faces with two equivalent Nb(5)O6 octahedra. In the fifth Ba site, Ba(5) is bonded to two equivalent O(10), two equivalent O(11), two equivalent O(13), two equivalent O(6), two equivalent O(7), and two equivalent O(9) atoms to form BaO12 cuboctahedra that share corners with two equivalent Ba(2)O12 cuboctahedra, corners with two equivalent Ba(3)O12 cuboctahedra, corners with two equivalent Ba(4)O12 cuboctahedra, corners with four equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, faces with two equivalent Ba(4)O12 cuboctahedra, faces with two equivalent Nb(2)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, faces with two equivalent Nb(4)O6 octahedra, and faces with two equivalent Nb(5)O6 octahedra. There are five inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(14), one O(16), one O(2), one O(3), and one O(4) atom to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Nb(5)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra,  a faceface with one Ba(2)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the second Nb site, Nb(2) is bonded to one O(13), one O(3), one O(5), one O(6), one O(8), and one O(9) atom to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(5)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with two equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-5°. In the third Nb site, Nb(3) is bonded to one O(1), one O(10), one O(4), one O(6), one O(7), and one O(8) atom to form NbO6 octahedra that share  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Nb(5)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra,  a faceface with one Ba(2)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with two equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-5°. In the fourth Nb site, Nb(4) is bonded to one O(10), one O(11), one O(13), one O(15), one O(2), and one O(5) atom to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(5)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(3)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-5°. In the fifth Nb site, Nb(5) is bonded to one O(11), one O(12), one O(14), one O(15), one O(7), and one O(9) atom to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(5)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra,  a faceface with one Ba(3)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded to one Ba(2), two equivalent Ba(1), one Nb(1), and one Nb(3) atom to form distorted OBa3Nb2 square pyramids that share  a cornercorner with one O(16)Ba4Nb2 octahedra,  a cornercorner with one O(6)Ba4Nb2 octahedra, corners with two equivalent O(13)Ba4Nb2 octahedra,  a cornercorner with one O(2)Ba3Nb2 square pyramid,  an edgeedge with one O(1)Ba3Nb2 square pyramid,  an edgeedge with one O(10)Ba3Nb2 square pyramid,  an edgeedge with one O(2)Ba3Nb2 square pyramid, and  an edgeedge with one O(3)Ba3Nb2 square pyramid. The corner-sharing octahedral tilt angles range from 3-58°. In the second O site, O(2) is bonded to one Ba(1), one Ba(3), one Ba(4), one Nb(1), and one Nb(4) atom to form distorted OBa3Nb2 square pyramids that share corners with two equivalent O(13)Ba4Nb2 octahedra, corners with three equivalent O(6)Ba4Nb2 octahedra,  a cornercorner with one O(1)Ba3Nb2 square pyramid,  a cornercorner with one O(3)Ba3Nb2 square pyramid,  an edgeedge with one O(1)Ba3Nb2 square pyramid,  an edgeedge with one O(10)Ba3Nb2 square pyramid,  an edgeedge with one O(3)Ba3Nb2 square pyramid, and  a faceface with one O(16)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the third O site, O(3) is bonded to one Ba(2), one Ba(3), one Ba(4), one Nb(1), and one Nb(2) atom to form distorted OBa3Nb2 square pyramids that share  a cornercorner with one O(13)Ba4Nb2 octahedra,  a cornercorner with one O(6)Ba4Nb2 octahedra,  a cornercorner with one O(2)Ba3Nb2 square pyramid, corners with two equivalent O(10)Ba3Nb2 square pyramids,  an edgeedge with one O(1)Ba3Nb2 square pyramid,  an edgeedge with one O(2)Ba3Nb2 square pyramid,  a faceface with one O(13)Ba4Nb2 octahedra,  a faceface with one O(16)Ba4Nb2 octahedra, and  a faceface with one O(6)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 58-59°. In the fourth O site, O(4) is bonded in a distorted linear geometry to one Ba(3), one Ba(4), two equivalent Ba(1), one Nb(1), and one Nb(3) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to one Ba(1), two equivalent Ba(2), one Nb(2), and one Nb(4) atom. In the sixth O site, O(6) is bonded to one Ba(4), one Ba(5), two equivalent Ba(3), one Nb(2), and one Nb(3) atom to form distorted OBa4Nb2 octahedra that share  a cornercorner with one O(13)Ba4Nb2 octahedra,  a cornercorner with one O(16)Ba4Nb2 octahedra,  a cornercorner with one O(6)Ba4Nb2 octahedra,  a cornercorner with one O(1)Ba3Nb2 square pyramid,  a cornercorner with one O(3)Ba3Nb2 square pyramid, corners with two equivalent O(10)Ba3Nb2 square pyramids, corners with three equivalent O(2)Ba3Nb2 square pyramids,  an edgeedge with one O(16)Ba4Nb2 octahedra,  an edgeedge with one O(6)Ba4Nb2 octahedra,  a faceface with one O(13)Ba4Nb2 octahedra,  a faceface with one O(10)Ba3Nb2 square pyramid, and  a faceface with one O(3)Ba3Nb2 square pyramid. The corner-sharing octahedral tilt angles range from 0-60°. In the seventh O site, O(7) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ba(4), one Ba(5), one Nb(3), and one Nb(5) atom. In the eighth O site, O(8) is bonded in a distorted linear geometry to one Ba(1), two equivalent Ba(3), one Nb(2), and one Nb(3) atom. In the ninth O site, O(9) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(5), one Nb(2), and one Nb(5) atom. In the tenth O site, O(10) is bonded to one Ba(2), one Ba(3), one Ba(5), one Nb(3), and one Nb(4) atom to form distorted OBa3Nb2 square pyramids that share  a cornercorner with one O(16)Ba4Nb2 octahedra, corners with two equivalent O(13)Ba4Nb2 octahedra, corners with two equivalent O(6)Ba4Nb2 octahedra,  a cornercorner with one O(10)Ba3Nb2 square pyramid, corners with two equivalent O(3)Ba3Nb2 square pyramids,  an edgeedge with one O(1)Ba3Nb2 square pyramid,  an edgeedge with one O(2)Ba3Nb2 square pyramid,  a faceface with one O(13)Ba4Nb2 octahedra, and  a faceface with one O(6)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 58-60°. In the eleventh O site, O(11) is bonded in a distorted linear geometry to one Ba(3), one Ba(5), two equivalent Ba(4), one Nb(4), and one Nb(5) atom. In the twelfth O site, O(12) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Nb(5) atoms. In the thirteenth O site, O(13) is bonded to one Ba(4), one Ba(5), two equivalent Ba(2), one Nb(2), and one Nb(4) atom to form distorted OBa4Nb2 octahedra that share  a cornercorner with one O(13)Ba4Nb2 octahedra,  a cornercorner with one O(16)Ba4Nb2 octahedra,  a cornercorner with one O(6)Ba4Nb2 octahedra,  a cornercorner with one O(3)Ba3Nb2 square pyramid, corners with two equivalent O(1)Ba3Nb2 square pyramids, corners with two equivalent O(10)Ba3Nb2 square pyramids, corners with two equivalent O(2)Ba3Nb2 square pyramids,  an edgeedge with one O(13)Ba4Nb2 octahedra,  a faceface with one O(6)Ba4Nb2 octahedra,  a faceface with one O(10)Ba3Nb2 square pyramid, and  a faceface with one O(3)Ba3Nb2 square pyramid. The corner-sharing octahedral tilt angles range from 0-60°. In the fourteenth O site, O(14) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), one Nb(1), and one Nb(5) atom. In the fifteenth O site, O(15) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), two equivalent Ba(4), one Nb(4), and one Nb(5) atom. In the sixteenth O site, O(16) is bonded to two equivalent Ba(3), two equivalent Ba(4), and two equivalent Nb(1) atoms to form distorted OBa4Nb2 octahedra that share corners with two equivalent O(13)Ba4Nb2 octahedra, corners with two equivalent O(6)Ba4Nb2 octahedra, corners with two equivalent O(1)Ba3Nb2 square pyramids, corners with two equivalent O(10)Ba3Nb2 square pyramids, edges with two equivalent O(6)Ba4Nb2 octahedra, faces with two equivalent O(2)Ba3Nb2 square pyramids, and faces with two equivalent O(3)Ba3Nb2 square pyramids. The corner-sharing octahedral tilt angles range from 2-60°.
Ba9Nb10O30 crystallizes in the triclinic P-1 space group. There are five inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(12), one O(14), one O(15), one O(2), one O(5), one O(7), one O(8), one O(9), two equivalent O(1), and two equivalent O(4) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(1)O12 cuboctahedra, corners with two equivalent Ba(2)O12 cuboctahedra, corners with two equivalent Ba(5)O12 cuboctahedra, corners with three equivalent Ba(3)O12 cuboctahedra, corners with three equivalent Ba(4)O12 cuboctahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(3)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra,  a faceface with one Nb(2)O6 octahedra,  a faceface with one Nb(4)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, and faces with two equivalent Nb(5)O6 octahedra. The Ba(1)-O(12) bond length is 2.94 Å. The Ba(1)-O(14) bond length is 2.94 Å. The Ba(1)-O(15) bond length is 2.91 Å. The Ba(1)-O(2) bond length is 2.88 Å. The Ba(1)-O(5) bond length is 2.88 Å. The Ba(1)-O(7) bond length is 2.95 Å. The Ba(1)-O(8) bond length is 2.87 Å. The Ba(1)-O(9) bond length is 2.91 Å. There is one shorter (2.87 Å) and one longer (2.89 Å) Ba(1)-O(1) bond length. Both Ba(1)-O(4) bond lengths are 2.91 Å. In the second Ba site, Ba(2) is bonded to one O(1), one O(10), one O(12), one O(14), one O(15), one O(3), one O(7), one O(9), two equivalent O(13), and two equivalent O(5) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(2)O12 cuboctahedra,  a cornercorner with one Ba(5)O12 cuboctahedra, corners with two equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ba(4)O12 cuboctahedra, corners with four equivalent Ba(3)O12 cuboctahedra,  a faceface with one Ba(2)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra,  a faceface with one Nb(1)O6 octahedra,  a faceface with one Nb(3)O6 octahedra, faces with two equivalent Nb(2)O6 octahedra, faces with two equivalent Nb(4)O6 octahedra, and faces with two equivalent Nb(5)O6 octahedra. The Ba(2)-O(1) bond length is 2.88 Å. The Ba(2)-O(10) bond length is 2.88 Å. The Ba(2)-O(12) bond length is 2.94 Å. The Ba(2)-O(14) bond length is 2.91 Å. The Ba(2)-O(15) bond length is 2.94 Å. The Ba(2)-O(3) bond length is 2.88 Å. The Ba(2)-O(7) bond length is 2.91 Å. The Ba(2)-O(9) bond length is 2.94 Å. Both Ba(2)-O(13) bond lengths are 2.91 Å. There is one shorter (2.88 Å) and one longer (2.90 Å) Ba(2)-O(5) bond length. In the third Ba site, Ba(3) is bonded to one O(10), one O(11), one O(14), one O(16), one O(2), one O(3), one O(4), one O(9), two equivalent O(6), and two equivalent O(8) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(3)O12 cuboctahedra,  a cornercorner with one Ba(5)O12 cuboctahedra, corners with two equivalent Ba(4)O12 cuboctahedra, corners with three equivalent Ba(1)O12 cuboctahedra, corners with four equivalent Ba(2)O12 cuboctahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(3)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(4)O12 cuboctahedra,  a faceface with one Nb(4)O6 octahedra,  a faceface with one Nb(5)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(2)O6 octahedra, and faces with two equivalent Nb(3)O6 octahedra. The Ba(3)-O(10) bond length is 2.89 Å. The Ba(3)-O(11) bond length is 2.91 Å. The Ba(3)-O(14) bond length is 2.94 Å. The Ba(3)-O(16) bond length is 2.90 Å. The Ba(3)-O(2) bond length is 2.89 Å. The Ba(3)-O(3) bond length is 2.88 Å. The Ba(3)-O(4) bond length is 2.93 Å. The Ba(3)-O(9) bond length is 2.94 Å. There is one shorter (2.90 Å) and one longer (2.91 Å) Ba(3)-O(6) bond length. Both Ba(3)-O(8) bond lengths are 2.89 Å. In the fourth Ba site, Ba(4) is bonded to one O(13), one O(14), one O(16), one O(2), one O(3), one O(4), one O(6), one O(7), two equivalent O(11), and two equivalent O(15) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(4)O12 cuboctahedra,  a cornercorner with one Ba(5)O12 cuboctahedra, corners with two equivalent Ba(3)O12 cuboctahedra, corners with three equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ba(2)O12 cuboctahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(2)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra,  a faceface with one Nb(2)O6 octahedra,  a faceface with one Nb(3)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(4)O6 octahedra, and faces with two equivalent Nb(5)O6 octahedra. The Ba(4)-O(13) bond length is 2.91 Å. The Ba(4)-O(14) bond length is 2.92 Å. The Ba(4)-O(16) bond length is 2.91 Å. The Ba(4)-O(2) bond length is 2.87 Å. The Ba(4)-O(3) bond length is 2.86 Å. The Ba(4)-O(4) bond length is 2.91 Å. The Ba(4)-O(6) bond length is 2.90 Å. The Ba(4)-O(7) bond length is 2.90 Å. There is one shorter (2.91 Å) and one longer (2.92 Å) Ba(4)-O(11) bond length. Both Ba(4)-O(15) bond lengths are 2.92 Å. In the fifth Ba site, Ba(5) is bonded to two equivalent O(10), two equivalent O(11), two equivalent O(13), two equivalent O(6), two equivalent O(7), and two equivalent O(9) atoms to form BaO12 cuboctahedra that share corners with two equivalent Ba(2)O12 cuboctahedra, corners with two equivalent Ba(3)O12 cuboctahedra, corners with two equivalent Ba(4)O12 cuboctahedra, corners with four equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, faces with two equivalent Ba(4)O12 cuboctahedra, faces with two equivalent Nb(2)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, faces with two equivalent Nb(4)O6 octahedra, and faces with two equivalent Nb(5)O6 octahedra. Both Ba(5)-O(10) bond lengths are 2.87 Å. Both Ba(5)-O(11) bond lengths are 2.91 Å. Both Ba(5)-O(13) bond lengths are 2.91 Å. Both Ba(5)-O(6) bond lengths are 2.91 Å. Both Ba(5)-O(7) bond lengths are 2.91 Å. Both Ba(5)-O(9) bond lengths are 2.91 Å. There are five inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(14), one O(16), one O(2), one O(3), and one O(4) atom to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Nb(5)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra,  a faceface with one Ba(2)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-5°. The Nb(1)-O(1) bond length is 2.04 Å. The Nb(1)-O(14) bond length is 2.09 Å. The Nb(1)-O(16) bond length is 2.08 Å. The Nb(1)-O(2) bond length is 2.03 Å. The Nb(1)-O(3) bond length is 2.04 Å. The Nb(1)-O(4) bond length is 2.08 Å. In the second Nb site, Nb(2) is bonded to one O(13), one O(3), one O(5), one O(6), one O(8), and one O(9) atom to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(5)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with two equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-5°. The Nb(2)-O(13) bond length is 2.08 Å. The Nb(2)-O(3) bond length is 2.03 Å. The Nb(2)-O(5) bond length is 2.04 Å. The Nb(2)-O(6) bond length is 2.08 Å. The Nb(2)-O(8) bond length is 2.04 Å. The Nb(2)-O(9) bond length is 2.08 Å. In the third Nb site, Nb(3) is bonded to one O(1), one O(10), one O(4), one O(6), one O(7), and one O(8) atom to form NbO6 octahedra that share  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Nb(5)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra,  a faceface with one Ba(2)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with two equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-5°. The Nb(3)-O(1) bond length is 2.04 Å. The Nb(3)-O(10) bond length is 2.04 Å. The Nb(3)-O(4) bond length is 2.08 Å. The Nb(3)-O(6) bond length is 2.08 Å. The Nb(3)-O(7) bond length is 2.09 Å. The Nb(3)-O(8) bond length is 2.03 Å. In the fourth Nb site, Nb(4) is bonded to one O(10), one O(11), one O(13), one O(15), one O(2), and one O(5) atom to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(5)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(3)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-5°. The Nb(4)-O(10) bond length is 2.03 Å. The Nb(4)-O(11) bond length is 2.09 Å. The Nb(4)-O(13) bond length is 2.08 Å. The Nb(4)-O(15) bond length is 2.09 Å. The Nb(4)-O(2) bond length is 2.03 Å. The Nb(4)-O(5) bond length is 2.03 Å. In the fifth Nb site, Nb(5) is bonded to one O(11), one O(12), one O(14), one O(15), one O(7), and one O(9) atom to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(5)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra,  a faceface with one Ba(3)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. The Nb(5)-O(11) bond length is 2.06 Å. The Nb(5)-O(12) bond length is 2.06 Å. The Nb(5)-O(14) bond length is 2.05 Å. The Nb(5)-O(15) bond length is 2.06 Å. The Nb(5)-O(7) bond length is 2.06 Å. The Nb(5)-O(9) bond length is 2.05 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded to one Ba(2), two equivalent Ba(1), one Nb(1), and one Nb(3) atom to form distorted OBa3Nb2 square pyramids that share  a cornercorner with one O(16)Ba4Nb2 octahedra,  a cornercorner with one O(6)Ba4Nb2 octahedra, corners with two equivalent O(13)Ba4Nb2 octahedra,  a cornercorner with one O(2)Ba3Nb2 square pyramid,  an edgeedge with one O(1)Ba3Nb2 square pyramid,  an edgeedge with one O(10)Ba3Nb2 square pyramid,  an edgeedge with one O(2)Ba3Nb2 square pyramid, and  an edgeedge with one O(3)Ba3Nb2 square pyramid. The corner-sharing octahedral tilt angles range from 3-58°. In the second O site, O(2) is bonded to one Ba(1), one Ba(3), one Ba(4), one Nb(1), and one Nb(4) atom to form distorted OBa3Nb2 square pyramids that share corners with two equivalent O(13)Ba4Nb2 octahedra, corners with three equivalent O(6)Ba4Nb2 octahedra,  a cornercorner with one O(1)Ba3Nb2 square pyramid,  a cornercorner with one O(3)Ba3Nb2 square pyramid,  an edgeedge with one O(1)Ba3Nb2 square pyramid,  an edgeedge with one O(10)Ba3Nb2 square pyramid,  an edgeedge with one O(3)Ba3Nb2 square pyramid, and  a faceface with one O(16)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the third O site, O(3) is bonded to one Ba(2), one Ba(3), one Ba(4), one Nb(1), and one Nb(2) atom to form distorted OBa3Nb2 square pyramids that share  a cornercorner with one O(13)Ba4Nb2 octahedra,  a cornercorner with one O(6)Ba4Nb2 octahedra,  a cornercorner with one O(2)Ba3Nb2 square pyramid, corners with two equivalent O(10)Ba3Nb2 square pyramids,  an edgeedge with one O(1)Ba3Nb2 square pyramid,  an edgeedge with one O(2)Ba3Nb2 square pyramid,  a faceface with one O(13)Ba4Nb2 octahedra,  a faceface with one O(16)Ba4Nb2 octahedra, and  a faceface with one O(6)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 58-59°. In the fourth O site, O(4) is bonded in a distorted linear geometry to one Ba(3), one Ba(4), two equivalent Ba(1), one Nb(1), and one Nb(3) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to one Ba(1), two equivalent Ba(2), one Nb(2), and one Nb(4) atom. In the sixth O site, O(6) is bonded to one Ba(4), one Ba(5), two equivalent Ba(3), one Nb(2), and one Nb(3) atom to form distorted OBa4Nb2 octahedra that share  a cornercorner with one O(13)Ba4Nb2 octahedra,  a cornercorner with one O(16)Ba4Nb2 octahedra,  a cornercorner with one O(6)Ba4Nb2 octahedra,  a cornercorner with one O(1)Ba3Nb2 square pyramid,  a cornercorner with one O(3)Ba3Nb2 square pyramid, corners with two equivalent O(10)Ba3Nb2 square pyramids, corners with three equivalent O(2)Ba3Nb2 square pyramids,  an edgeedge with one O(16)Ba4Nb2 octahedra,  an edgeedge with one O(6)Ba4Nb2 octahedra,  a faceface with one O(13)Ba4Nb2 octahedra,  a faceface with one O(10)Ba3Nb2 square pyramid, and  a faceface with one O(3)Ba3Nb2 square pyramid. The corner-sharing octahedral tilt angles range from 0-60°. In the seventh O site, O(7) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ba(4), one Ba(5), one Nb(3), and one Nb(5) atom. In the eighth O site, O(8) is bonded in a distorted linear geometry to one Ba(1), two equivalent Ba(3), one Nb(2), and one Nb(3) atom. In the ninth O site, O(9) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(5), one Nb(2), and one Nb(5) atom. In the tenth O site, O(10) is bonded to one Ba(2), one Ba(3), one Ba(5), one Nb(3), and one Nb(4) atom to form distorted OBa3Nb2 square pyramids that share  a cornercorner with one O(16)Ba4Nb2 octahedra, corners with two equivalent O(13)Ba4Nb2 octahedra, corners with two equivalent O(6)Ba4Nb2 octahedra,  a cornercorner with one O(10)Ba3Nb2 square pyramid, corners with two equivalent O(3)Ba3Nb2 square pyramids,  an edgeedge with one O(1)Ba3Nb2 square pyramid,  an edgeedge with one O(2)Ba3Nb2 square pyramid,  a faceface with one O(13)Ba4Nb2 octahedra, and  a faceface with one O(6)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 58-60°. In the eleventh O site, O(11) is bonded in a distorted linear geometry to one Ba(3), one Ba(5), two equivalent Ba(4), one Nb(4), and one Nb(5) atom. In the twelfth O site, O(12) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Nb(5) atoms. In the thirteenth O site, O(13) is bonded to one Ba(4), one Ba(5), two equivalent Ba(2), one Nb(2), and one Nb(4) atom to form distorted OBa4Nb2 octahedra that share  a cornercorner with one O(13)Ba4Nb2 octahedra,  a cornercorner with one O(16)Ba4Nb2 octahedra,  a cornercorner with one O(6)Ba4Nb2 octahedra,  a cornercorner with one O(3)Ba3Nb2 square pyramid, corners with two equivalent O(1)Ba3Nb2 square pyramids, corners with two equivalent O(10)Ba3Nb2 square pyramids, corners with two equivalent O(2)Ba3Nb2 square pyramids,  an edgeedge with one O(13)Ba4Nb2 octahedra,  a faceface with one O(6)Ba4Nb2 octahedra,  a faceface with one O(10)Ba3Nb2 square pyramid, and  a faceface with one O(3)Ba3Nb2 square pyramid. The corner-sharing octahedral tilt angles range from 0-60°. In the fourteenth O site, O(14) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), one Nb(1), and one Nb(5) atom. In the fifteenth O site, O(15) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), two equivalent Ba(4), one Nb(4), and one Nb(5) atom. In the sixteenth O site, O(16) is bonded to two equivalent Ba(3), two equivalent Ba(4), and two equivalent Nb(1) atoms to form distorted OBa4Nb2 octahedra that share corners with two equivalent O(13)Ba4Nb2 octahedra, corners with two equivalent O(6)Ba4Nb2 octahedra, corners with two equivalent O(1)Ba3Nb2 square pyramids, corners with two equivalent O(10)Ba3Nb2 square pyramids, edges with two equivalent O(6)Ba4Nb2 octahedra, faces with two equivalent O(2)Ba3Nb2 square pyramids, and faces with two equivalent O(3)Ba3Nb2 square pyramids. The corner-sharing octahedral tilt angles range from 2-60°.