Hf(TlSe)4 crystallizes in the triclinic P-1 space group. There are three inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one Se(1), one Se(10), one Se(6), one Se(8), and two equivalent Se(2) atoms to form edge-sharing HfSe6 octahedra. In the second Hf site, Hf(2) is bonded to one Se(10), one Se(3), one Se(4), one Se(5), one Se(6), and one Se(7) atom to form edge-sharing HfSe6 octahedra. In the third Hf site, Hf(3) is bonded to two equivalent Se(3), two equivalent Se(4), and two equivalent Se(9) atoms to form edge-sharing HfSe6 octahedra. There are ten inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 3-coordinate geometry to one Se(1), one Se(10), and one Se(5) atom. In the second Tl site, Tl(2) is bonded in a 3-coordinate geometry to one Se(2), one Se(6), and one Se(8) atom. In the third Tl site, Tl(3) is bonded in a distorted rectangular see-saw-like geometry to one Se(2), one Se(8), and two equivalent Se(1) atoms. In the fourth Tl site, Tl(4) is bonded in a 3-coordinate geometry to one Se(10), one Se(2), one Se(4), and one Se(9) atom. In the fifth Tl site, Tl(5) is bonded in a 3-coordinate geometry to one Se(1), one Se(5), and one Se(6) atom. In the sixth Tl site, Tl(6) is bonded in a 3-coordinate geometry to one Se(4), one Se(7), and one Se(9) atom. In the seventh Tl site, Tl(7) is bonded in a 3-coordinate geometry to one Se(2), one Se(7), and one Se(8) atom. In the eighth Tl site, Tl(8) is bonded in a 4-coordinate geometry to one Se(10), one Se(5), one Se(7), and one Se(8) atom. In the ninth Tl site, Tl(9) is bonded in a 3-coordinate geometry to one Se(3), one Se(7), and one Se(9) atom. In the tenth Tl site, Tl(10) is bonded in a 3-coordinate geometry to one Se(10), one Se(3), one Se(5), and one Se(9) atom. There are ten inequivalent Se sites. In the first Se site, Se(1) is bonded to one Hf(1), one Tl(1), one Tl(5), and two equivalent Tl(3) atoms to form distorted edge-sharing SeHfTl4 square pyramids. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Hf(1), one Tl(2), one Tl(3), one Tl(4), and one Tl(7) atom. In the third Se site, Se(3) is bonded in a distorted rectangular see-saw-like geometry to one Hf(2), one Hf(3), one Tl(10), and one Tl(9) atom. In the fourth Se site, Se(4) is bonded in a 4-coordinate geometry to one Hf(2), one Hf(3), one Tl(4), and one Tl(6) atom. In the fifth Se site, Se(5) is bonded in a 5-coordinate geometry to one Hf(2), one Tl(1), one Tl(10), one Tl(5), and one Tl(8) atom. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to one Hf(1), one Hf(2), one Tl(2), and one Tl(5) atom. In the seventh Se site, Se(7) is bonded to one Hf(2), one Tl(6), one Tl(7), one Tl(8), and one Tl(9) atom to form distorted edge-sharing SeHfTl4 square pyramids. In the eighth Se site, Se(8) is bonded in a 5-coordinate geometry to one Hf(1), one Tl(2), one Tl(3), one Tl(7), and one Tl(8) atom. In the ninth Se site, Se(9) is bonded to one Hf(3), one Tl(10), one Tl(4), one Tl(6), and one Tl(9) atom to form a mixture of distorted corner and edge-sharing SeHfTl4 square pyramids. In the tenth Se site, Se(10) is bonded in a 6-coordinate geometry to one Hf(1), one Hf(2), one Tl(1), one Tl(10), one Tl(4), and one Tl(8) atom.
Hf(TlSe)4 crystallizes in the triclinic P-1 space group. There are three inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one Se(1), one Se(10), one Se(6), one Se(8), and two equivalent Se(2) atoms to form edge-sharing HfSe6 octahedra. The Hf(1)-Se(1) bond length is 2.66 Å. The Hf(1)-Se(10) bond length is 2.72 Å. The Hf(1)-Se(6) bond length is 2.78 Å. The Hf(1)-Se(8) bond length is 2.66 Å. There is one shorter (2.72 Å) and one longer (2.75 Å) Hf(1)-Se(2) bond length. In the second Hf site, Hf(2) is bonded to one Se(10), one Se(3), one Se(4), one Se(5), one Se(6), and one Se(7) atom to form edge-sharing HfSe6 octahedra. The Hf(2)-Se(10) bond length is 2.75 Å. The Hf(2)-Se(3) bond length is 2.75 Å. The Hf(2)-Se(4) bond length is 2.79 Å. The Hf(2)-Se(5) bond length is 2.65 Å. The Hf(2)-Se(6) bond length is 2.74 Å. The Hf(2)-Se(7) bond length is 2.66 Å. In the third Hf site, Hf(3) is bonded to two equivalent Se(3), two equivalent Se(4), and two equivalent Se(9) atoms to form edge-sharing HfSe6 octahedra. Both Hf(3)-Se(3) bond lengths are 2.72 Å. Both Hf(3)-Se(4) bond lengths are 2.74 Å. Both Hf(3)-Se(9) bond lengths are 2.70 Å. There are ten inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 3-coordinate geometry to one Se(1), one Se(10), and one Se(5) atom. The Tl(1)-Se(1) bond length is 3.13 Å. The Tl(1)-Se(10) bond length is 3.22 Å. The Tl(1)-Se(5) bond length is 3.02 Å. In the second Tl site, Tl(2) is bonded in a 3-coordinate geometry to one Se(2), one Se(6), and one Se(8) atom. The Tl(2)-Se(2) bond length is 3.08 Å. The Tl(2)-Se(6) bond length is 3.14 Å. The Tl(2)-Se(8) bond length is 3.15 Å. In the third Tl site, Tl(3) is bonded in a distorted rectangular see-saw-like geometry to one Se(2), one Se(8), and two equivalent Se(1) atoms. The Tl(3)-Se(2) bond length is 3.34 Å. The Tl(3)-Se(8) bond length is 3.22 Å. There is one shorter (3.01 Å) and one longer (3.07 Å) Tl(3)-Se(1) bond length. In the fourth Tl site, Tl(4) is bonded in a 3-coordinate geometry to one Se(10), one Se(2), one Se(4), and one Se(9) atom. The Tl(4)-Se(10) bond length is 3.05 Å. The Tl(4)-Se(2) bond length is 3.41 Å. The Tl(4)-Se(4) bond length is 3.13 Å. The Tl(4)-Se(9) bond length is 3.11 Å. In the fifth Tl site, Tl(5) is bonded in a 3-coordinate geometry to one Se(1), one Se(5), and one Se(6) atom. The Tl(5)-Se(1) bond length is 3.11 Å. The Tl(5)-Se(5) bond length is 3.04 Å. The Tl(5)-Se(6) bond length is 3.04 Å. In the sixth Tl site, Tl(6) is bonded in a 3-coordinate geometry to one Se(4), one Se(7), and one Se(9) atom. The Tl(6)-Se(4) bond length is 3.02 Å. The Tl(6)-Se(7) bond length is 3.11 Å. The Tl(6)-Se(9) bond length is 3.04 Å. In the seventh Tl site, Tl(7) is bonded in a 3-coordinate geometry to one Se(2), one Se(7), and one Se(8) atom. The Tl(7)-Se(2) bond length is 3.24 Å. The Tl(7)-Se(7) bond length is 3.22 Å. The Tl(7)-Se(8) bond length is 3.03 Å. In the eighth Tl site, Tl(8) is bonded in a 4-coordinate geometry to one Se(10), one Se(5), one Se(7), and one Se(8) atom. The Tl(8)-Se(10) bond length is 3.36 Å. The Tl(8)-Se(5) bond length is 3.24 Å. The Tl(8)-Se(7) bond length is 3.00 Å. The Tl(8)-Se(8) bond length is 3.09 Å. In the ninth Tl site, Tl(9) is bonded in a 3-coordinate geometry to one Se(3), one Se(7), and one Se(9) atom. The Tl(9)-Se(3) bond length is 3.17 Å. The Tl(9)-Se(7) bond length is 3.03 Å. The Tl(9)-Se(9) bond length is 3.01 Å. In the tenth Tl site, Tl(10) is bonded in a 3-coordinate geometry to one Se(10), one Se(3), one Se(5), and one Se(9) atom. The Tl(10)-Se(10) bond length is 3.39 Å. The Tl(10)-Se(3) bond length is 3.05 Å. The Tl(10)-Se(5) bond length is 3.20 Å. The Tl(10)-Se(9) bond length is 3.16 Å. There are ten inequivalent Se sites. In the first Se site, Se(1) is bonded to one Hf(1), one Tl(1), one Tl(5), and two equivalent Tl(3) atoms to form distorted edge-sharing SeHfTl4 square pyramids. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Hf(1), one Tl(2), one Tl(3), one Tl(4), and one Tl(7) atom. In the third Se site, Se(3) is bonded in a distorted rectangular see-saw-like geometry to one Hf(2), one Hf(3), one Tl(10), and one Tl(9) atom. In the fourth Se site, Se(4) is bonded in a 4-coordinate geometry to one Hf(2), one Hf(3), one Tl(4), and one Tl(6) atom. In the fifth Se site, Se(5) is bonded in a 5-coordinate geometry to one Hf(2), one Tl(1), one Tl(10), one Tl(5), and one Tl(8) atom. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to one Hf(1), one Hf(2), one Tl(2), and one Tl(5) atom. In the seventh Se site, Se(7) is bonded to one Hf(2), one Tl(6), one Tl(7), one Tl(8), and one Tl(9) atom to form distorted edge-sharing SeHfTl4 square pyramids. In the eighth Se site, Se(8) is bonded in a 5-coordinate geometry to one Hf(1), one Tl(2), one Tl(3), one Tl(7), and one Tl(8) atom. In the ninth Se site, Se(9) is bonded to one Hf(3), one Tl(10), one Tl(4), one Tl(6), and one Tl(9) atom to form a mixture of distorted corner and edge-sharing SeHfTl4 square pyramids. In the tenth Se site, Se(10) is bonded in a 6-coordinate geometry to one Hf(1), one Hf(2), one Tl(1), one Tl(10), one Tl(4), and one Tl(8) atom.