Ba3Te2O9 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 12-coordinate geometry to three equivalent O(2) and nine equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(2)O12 cuboctahedra and faces with six equivalent Te(1)O6 octahedra. Te(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted TeO6 octahedra that share faces with three equivalent Ba(2)O12 cuboctahedra and  a faceface with one Te(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(2), three equivalent Ba(1), and one Te(1) atom. In the second O site, O(2) is bonded in a distorted L-shaped geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Te(1) atoms.
Ba3Te2O9 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 12-coordinate geometry to three equivalent O(2) and nine equivalent O(1) atoms. All Ba(1)-O(2) bond lengths are 3.34 Å. There are three shorter (2.80 Å) and six longer (2.98 Å) Ba(1)-O(1) bond lengths. In the second Ba site, Ba(2) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(2)O12 cuboctahedra and faces with six equivalent Te(1)O6 octahedra. All Ba(2)-O(1) bond lengths are 2.87 Å. All Ba(2)-O(2) bond lengths are 2.96 Å. Te(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted TeO6 octahedra that share faces with three equivalent Ba(2)O12 cuboctahedra and  a faceface with one Te(1)O6 octahedra. All Te(1)-O(1) bond lengths are 1.86 Å. All Te(1)-O(2) bond lengths are 2.05 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(2), three equivalent Ba(1), and one Te(1) atom. In the second O site, O(2) is bonded in a distorted L-shaped geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Te(1) atoms.