BaTb2SmO6 crystallizes in the tetragonal P4_2/mmc space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. In the second Ba site, Ba(2) is bonded to four equivalent O(3) and eight equivalent O(2) atoms to form distorted BaO12 cuboctahedra that share faces with two equivalent Ba(2)O12 cuboctahedra and faces with eight equivalent Tb(1)O6 octahedra. Tb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TbO6 octahedra that share corners with six equivalent Tb(1)O6 octahedra and faces with two equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 18-40°. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. In the second Sm site, Sm(2) is bonded in a square co-planar geometry to four equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(3) is bonded in a 3-coordinate geometry to one Ba(2), two equivalent Tb(1), and one Sm(2) atom. In the second O site, O(1) is bonded to one Ba(1), two equivalent Tb(1), and one Sm(1) atom to form a mixture of distorted corner and edge-sharing OBaTb2Sm tetrahedra. In the third O site, O(2) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Ba(2), and two equivalent Tb(1) atoms.
BaTb2SmO6 crystallizes in the tetragonal P4_2/mmc space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Ba(1)-O(1) bond lengths are 2.91 Å. All Ba(1)-O(2) bond lengths are 2.78 Å. In the second Ba site, Ba(2) is bonded to four equivalent O(3) and eight equivalent O(2) atoms to form distorted BaO12 cuboctahedra that share faces with two equivalent Ba(2)O12 cuboctahedra and faces with eight equivalent Tb(1)O6 octahedra. All Ba(2)-O(3) bond lengths are 3.30 Å. There are four shorter (2.94 Å) and four longer (3.40 Å) Ba(2)-O(2) bond lengths. Tb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TbO6 octahedra that share corners with six equivalent Tb(1)O6 octahedra and faces with two equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 18-40°. Both Tb(1)-O(1) bond lengths are 2.26 Å. Both Tb(1)-O(2) bond lengths are 2.24 Å. Both Tb(1)-O(3) bond lengths are 2.33 Å. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. All Sm(1)-O(1) bond lengths are 2.35 Å. In the second Sm site, Sm(2) is bonded in a square co-planar geometry to four equivalent O(3) atoms. All Sm(2)-O(3) bond lengths are 2.32 Å. There are three inequivalent O sites. In the first O site, O(3) is bonded in a 3-coordinate geometry to one Ba(2), two equivalent Tb(1), and one Sm(2) atom. In the second O site, O(1) is bonded to one Ba(1), two equivalent Tb(1), and one Sm(1) atom to form a mixture of distorted corner and edge-sharing OBaTb2Sm tetrahedra. In the third O site, O(2) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Ba(2), and two equivalent Tb(1) atoms.