Mo9Tl2S11 crystallizes in the trigonal R-3 space group. There are three inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one S(1), one S(2), and three equivalent S(4) atoms to form distorted MoS5 square pyramids that share corners with three equivalent Mo(2)S5 square pyramids,  a cornercorner with one Tl(2)S4 trigonal pyramid,  an edgeedge with one Mo(2)S5 square pyramid, and edges with four equivalent Mo(1)S5 square pyramids. In the second Mo site, Mo(2) is bonded to one S(3), one S(4), one S(5), and two equivalent S(2) atoms to form distorted MoS5 square pyramids that share corners with three equivalent Mo(1)S5 square pyramids, corners with three equivalent Tl(2)S4 trigonal pyramids,  an edgeedge with one Mo(1)S5 square pyramid, and edges with two equivalent Mo(2)S5 square pyramids. In the third Mo site, Mo(3) is bonded in a distorted see-saw-like geometry to one S(2) and three equivalent S(3) atoms. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a single-bond geometry to one S(1) atom. In the second Tl site, Tl(2) is bonded to one S(5) and three equivalent S(2) atoms to form distorted TlS4 trigonal pyramids that share corners with three equivalent Mo(1)S5 square pyramids and corners with nine equivalent Mo(2)S5 square pyramids. There are five inequivalent S sites. In the first S site, S(1) is bonded in a 4-coordinate geometry to three equivalent Mo(1) and one Tl(1) atom. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Mo(1), one Mo(3), two equivalent Mo(2), and one Tl(2) atom. In the third S site, S(3) is bonded in a 4-coordinate geometry to one Mo(2) and three equivalent Mo(3) atoms. In the fourth S site, S(4) is bonded in a 4-coordinate geometry to one Mo(2) and three equivalent Mo(1) atoms. In the fifth S site, S(5) is bonded in a 4-coordinate geometry to three equivalent Mo(2) and one Tl(2) atom.
Mo9Tl2S11 crystallizes in the trigonal R-3 space group. There are three inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one S(1), one S(2), and three equivalent S(4) atoms to form distorted MoS5 square pyramids that share corners with three equivalent Mo(2)S5 square pyramids,  a cornercorner with one Tl(2)S4 trigonal pyramid,  an edgeedge with one Mo(2)S5 square pyramid, and edges with four equivalent Mo(1)S5 square pyramids. The Mo(1)-S(1) bond length is 2.42 Å. The Mo(1)-S(2) bond length is 2.47 Å. There are a spread of Mo(1)-S(4) bond distances ranging from 2.44-2.48 Å. In the second Mo site, Mo(2) is bonded to one S(3), one S(4), one S(5), and two equivalent S(2) atoms to form distorted MoS5 square pyramids that share corners with three equivalent Mo(1)S5 square pyramids, corners with three equivalent Tl(2)S4 trigonal pyramids,  an edgeedge with one Mo(1)S5 square pyramid, and edges with two equivalent Mo(2)S5 square pyramids. The Mo(2)-S(3) bond length is 2.62 Å. The Mo(2)-S(4) bond length is 2.51 Å. The Mo(2)-S(5) bond length is 2.40 Å. There is one shorter (2.47 Å) and one longer (2.48 Å) Mo(2)-S(2) bond length. In the third Mo site, Mo(3) is bonded in a distorted see-saw-like geometry to one S(2) and three equivalent S(3) atoms. The Mo(3)-S(2) bond length is 2.44 Å. There are two shorter (2.49 Å) and one longer (2.59 Å) Mo(3)-S(3) bond length. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a single-bond geometry to one S(1) atom. The Tl(1)-S(1) bond length is 2.97 Å. In the second Tl site, Tl(2) is bonded to one S(5) and three equivalent S(2) atoms to form distorted TlS4 trigonal pyramids that share corners with three equivalent Mo(1)S5 square pyramids and corners with nine equivalent Mo(2)S5 square pyramids. The Tl(2)-S(5) bond length is 2.94 Å. All Tl(2)-S(2) bond lengths are 3.17 Å. There are five inequivalent S sites. In the first S site, S(1) is bonded in a 4-coordinate geometry to three equivalent Mo(1) and one Tl(1) atom. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Mo(1), one Mo(3), two equivalent Mo(2), and one Tl(2) atom. In the third S site, S(3) is bonded in a 4-coordinate geometry to one Mo(2) and three equivalent Mo(3) atoms. In the fourth S site, S(4) is bonded in a 4-coordinate geometry to one Mo(2) and three equivalent Mo(1) atoms. In the fifth S site, S(5) is bonded in a 4-coordinate geometry to three equivalent Mo(2) and one Tl(2) atom.