MnTlO3 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 34-37°. In the second Mn site, Mn(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 31-34°. Tl(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mn(1), one Mn(2), and two equivalent Tl(1) atoms to form distorted corner-sharing OMn2Tl2 tetrahedra. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mn(2) and one Tl(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Mn(1) and one Tl(1) atom.
MnTlO3 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 34-37°. Both Mn(1)-O(1) bond lengths are 1.96 Å. There are two shorter (2.04 Å) and two longer (2.08 Å) Mn(1)-O(3) bond lengths. In the second Mn site, Mn(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 31-34°. Both Mn(2)-O(1) bond lengths are 2.19 Å. All Mn(2)-O(2) bond lengths are 2.03 Å. Tl(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. The Tl(1)-O(2) bond length is 2.18 Å. The Tl(1)-O(3) bond length is 2.19 Å. There is one shorter (2.20 Å) and one longer (2.49 Å) Tl(1)-O(1) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mn(1), one Mn(2), and two equivalent Tl(1) atoms to form distorted corner-sharing OMn2Tl2 tetrahedra. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mn(2) and one Tl(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Mn(1) and one Tl(1) atom.