Ba2CuTeO6 crystallizes in the triclinic P-1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(2), one O(4), one O(5), three equivalent O(1), three equivalent O(3), and three equivalent O(6) atoms to form distorted BaO12 cuboctahedra that share corners with three equivalent Ba(2)O12 cuboctahedra, corners with six equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra,  a faceface with one Te(1)O6 octahedra, and faces with three equivalent Te(2)O6 octahedra. In the second Ba site, Ba(2) is bonded to one O(1), one O(3), one O(6), three equivalent O(2), three equivalent O(4), and three equivalent O(5) atoms to form distorted BaO12 cuboctahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with six equivalent Ba(2)O12 cuboctahedra, corners with three equivalent Te(2)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with three equivalent Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-28°. Cu(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form TeO6 octahedra that share faces with two equivalent Ba(1)O12 cuboctahedra and faces with six equivalent Ba(2)O12 cuboctahedra. In the second Te site, Te(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(6) atoms to form TeO6 octahedra that share corners with six equivalent Ba(2)O12 cuboctahedra and faces with six equivalent Ba(1)O12 cuboctahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Ba(2), three equivalent Ba(1), one Cu(1), and one Te(2) atom. In the second O site, O(2) is bonded in a distorted linear geometry to one Ba(1), three equivalent Ba(2), one Cu(1), and one Te(1) atom. In the third O site, O(3) is bonded in a distorted L-shaped geometry to one Ba(2), three equivalent Ba(1), one Cu(1), and one Te(2) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Ba(1), three equivalent Ba(2), one Cu(1), and one Te(1) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to one Ba(1), three equivalent Ba(2), one Cu(1), and one Te(1) atom. In the sixth O site, O(6) is bonded in a distorted L-shaped geometry to one Ba(2), three equivalent Ba(1), one Cu(1), and one Te(2) atom.
Ba2CuTeO6 crystallizes in the triclinic P-1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(2), one O(4), one O(5), three equivalent O(1), three equivalent O(3), and three equivalent O(6) atoms to form distorted BaO12 cuboctahedra that share corners with three equivalent Ba(2)O12 cuboctahedra, corners with six equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra,  a faceface with one Te(1)O6 octahedra, and faces with three equivalent Te(2)O6 octahedra. The Ba(1)-O(2) bond length is 3.05 Å. The Ba(1)-O(4) bond length is 2.79 Å. The Ba(1)-O(5) bond length is 3.10 Å. There is one shorter (2.74 Å) and two longer (2.88 Å) Ba(1)-O(1) bond lengths. There are a spread of Ba(1)-O(3) bond distances ranging from 2.83-3.12 Å. There are a spread of Ba(1)-O(6) bond distances ranging from 2.83-3.11 Å. In the second Ba site, Ba(2) is bonded to one O(1), one O(3), one O(6), three equivalent O(2), three equivalent O(4), and three equivalent O(5) atoms to form distorted BaO12 cuboctahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with six equivalent Ba(2)O12 cuboctahedra, corners with three equivalent Te(2)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with three equivalent Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-28°. The Ba(2)-O(1) bond length is 2.97 Å. The Ba(2)-O(3) bond length is 2.88 Å. The Ba(2)-O(6) bond length is 2.89 Å. There are a spread of Ba(2)-O(2) bond distances ranging from 2.89-3.06 Å. There are a spread of Ba(2)-O(4) bond distances ranging from 2.88-3.21 Å. There are a spread of Ba(2)-O(5) bond distances ranging from 2.90-3.02 Å. Cu(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Cu(1)-O(1) bond length is 2.53 Å. The Cu(1)-O(2) bond length is 1.96 Å. The Cu(1)-O(3) bond length is 2.04 Å. The Cu(1)-O(4) bond length is 2.19 Å. The Cu(1)-O(5) bond length is 1.96 Å. The Cu(1)-O(6) bond length is 2.04 Å. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form TeO6 octahedra that share faces with two equivalent Ba(1)O12 cuboctahedra and faces with six equivalent Ba(2)O12 cuboctahedra. Both Te(1)-O(2) bond lengths are 1.95 Å. Both Te(1)-O(4) bond lengths are 1.92 Å. Both Te(1)-O(5) bond lengths are 1.95 Å. In the second Te site, Te(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(6) atoms to form TeO6 octahedra that share corners with six equivalent Ba(2)O12 cuboctahedra and faces with six equivalent Ba(1)O12 cuboctahedra. Both Te(2)-O(1) bond lengths are 1.93 Å. Both Te(2)-O(3) bond lengths are 1.94 Å. Both Te(2)-O(6) bond lengths are 1.94 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Ba(2), three equivalent Ba(1), one Cu(1), and one Te(2) atom. In the second O site, O(2) is bonded in a distorted linear geometry to one Ba(1), three equivalent Ba(2), one Cu(1), and one Te(1) atom. In the third O site, O(3) is bonded in a distorted L-shaped geometry to one Ba(2), three equivalent Ba(1), one Cu(1), and one Te(2) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Ba(1), three equivalent Ba(2), one Cu(1), and one Te(1) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to one Ba(1), three equivalent Ba(2), one Cu(1), and one Te(1) atom. In the sixth O site, O(6) is bonded in a distorted L-shaped geometry to one Ba(2), three equivalent Ba(1), one Cu(1), and one Te(2) atom.