Ba2Ni2TlAlO7 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(1), and four equivalent O(2) atoms. Ni(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. Tl(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form a mixture of edge and corner-sharing TlO6 octahedra. The corner-sharing octahedra are not tilted. Al(1) is bonded in a body-centered cubic geometry to eight equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ba(1) and one Tl(1) atom to form distorted OBa4Tl trigonal bipyramids that share corners with five equivalent O(1)Ba4Tl trigonal bipyramids, edges with four equivalent O(3)Ba2Tl4 octahedra, and edges with four equivalent O(1)Ba4Tl trigonal bipyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1), two equivalent Ni(1), and two equivalent Al(1) atoms. In the third O site, O(3) is bonded to two equivalent Ba(1) and four equivalent Tl(1) atoms to form OBa2Tl4 octahedra that share corners with four equivalent O(3)Ba2Tl4 octahedra, edges with four equivalent O(3)Ba2Tl4 octahedra, and edges with eight equivalent O(1)Ba4Tl trigonal bipyramids. The corner-sharing octahedra are not tilted.
Ba2Ni2TlAlO7 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(1), and four equivalent O(2) atoms. The Ba(1)-O(3) bond length is 2.81 Å. All Ba(1)-O(1) bond lengths are 2.69 Å. All Ba(1)-O(2) bond lengths are 3.11 Å. Ni(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. All Ni(1)-O(2) bond lengths are 1.86 Å. Tl(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form a mixture of edge and corner-sharing TlO6 octahedra. The corner-sharing octahedra are not tilted. Both Tl(1)-O(1) bond lengths are 2.13 Å. All Tl(1)-O(3) bond lengths are 2.60 Å. Al(1) is bonded in a body-centered cubic geometry to eight equivalent O(2) atoms. All Al(1)-O(2) bond lengths are 2.22 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ba(1) and one Tl(1) atom to form distorted OBa4Tl trigonal bipyramids that share corners with five equivalent O(1)Ba4Tl trigonal bipyramids, edges with four equivalent O(3)Ba2Tl4 octahedra, and edges with four equivalent O(1)Ba4Tl trigonal bipyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1), two equivalent Ni(1), and two equivalent Al(1) atoms. In the third O site, O(3) is bonded to two equivalent Ba(1) and four equivalent Tl(1) atoms to form OBa2Tl4 octahedra that share corners with four equivalent O(3)Ba2Tl4 octahedra, edges with four equivalent O(3)Ba2Tl4 octahedra, and edges with eight equivalent O(1)Ba4Tl trigonal bipyramids. The corner-sharing octahedra are not tilted.