Ba2YCr2TlO7 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded to one O(3) and four equivalent O(1) atoms to form distorted BaO5 square pyramids that share corners with four equivalent Cr(1)O5 square pyramids, corners with five equivalent Ba(1)O5 square pyramids, edges with four equivalent Tl(1)O6 octahedra, and edges with four equivalent Ba(1)O5 square pyramids. Y(1) is bonded in a body-centered cubic geometry to eight equivalent O(2) atoms. Cr(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted CrO5 square pyramids that share  a cornercorner with one Tl(1)O6 octahedra, corners with four equivalent Ba(1)O5 square pyramids, and corners with four equivalent Cr(1)O5 square pyramids. The corner-sharing octahedra are not tilted. Tl(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form TlO6 octahedra that share corners with four equivalent Tl(1)O6 octahedra, corners with two equivalent Cr(1)O5 square pyramids, edges with four equivalent Tl(1)O6 octahedra, and edges with eight equivalent Ba(1)O5 square pyramids. The corner-sharing octahedra are not tilted. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to four equivalent Ba(1), one Cr(1), and one Tl(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Y(1) and two equivalent Cr(1) atoms. In the third O site, O(3) is bonded to two equivalent Ba(1) and four equivalent Tl(1) atoms to form a mixture of corner and edge-sharing OBa2Tl4 octahedra. The corner-sharing octahedra are not tilted.
Ba2YCr2TlO7 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded to one O(3) and four equivalent O(1) atoms to form distorted BaO5 square pyramids that share corners with four equivalent Cr(1)O5 square pyramids, corners with five equivalent Ba(1)O5 square pyramids, edges with four equivalent Tl(1)O6 octahedra, and edges with four equivalent Ba(1)O5 square pyramids. The Ba(1)-O(3) bond length is 2.59 Å. All Ba(1)-O(1) bond lengths are 2.80 Å. Y(1) is bonded in a body-centered cubic geometry to eight equivalent O(2) atoms. All Y(1)-O(2) bond lengths are 2.43 Å. Cr(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted CrO5 square pyramids that share  a cornercorner with one Tl(1)O6 octahedra, corners with four equivalent Ba(1)O5 square pyramids, and corners with four equivalent Cr(1)O5 square pyramids. The corner-sharing octahedra are not tilted. The Cr(1)-O(1) bond length is 1.92 Å. All Cr(1)-O(2) bond lengths are 2.02 Å. Tl(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form TlO6 octahedra that share corners with four equivalent Tl(1)O6 octahedra, corners with two equivalent Cr(1)O5 square pyramids, edges with four equivalent Tl(1)O6 octahedra, and edges with eight equivalent Ba(1)O5 square pyramids. The corner-sharing octahedra are not tilted. Both Tl(1)-O(1) bond lengths are 2.83 Å. All Tl(1)-O(3) bond lengths are 2.79 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to four equivalent Ba(1), one Cr(1), and one Tl(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Y(1) and two equivalent Cr(1) atoms. In the third O site, O(3) is bonded to two equivalent Ba(1) and four equivalent Tl(1) atoms to form a mixture of corner and edge-sharing OBa2Tl4 octahedra. The corner-sharing octahedra are not tilted.