SnBi2Te4 crystallizes in the monoclinic Cm space group. There are five inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one Te(13), one Te(4), two equivalent Te(8), and two equivalent Te(9) atoms to form SnTe6 octahedra that share  a cornercorner with one Sn(2)Te6 octahedra,  a cornercorner with one Bi(2)Te6 octahedra, corners with two equivalent Bi(3)Te6 octahedra, corners with two equivalent Bi(7)Te6 octahedra,  an edgeedge with one Bi(3)Te6 octahedra,  an edgeedge with one Bi(7)Te6 octahedra, edges with two equivalent Sn(1)Te6 octahedra, edges with two equivalent Sn(3)Te6 octahedra, edges with two equivalent Bi(4)Te6 octahedra, edges with two equivalent Bi(5)Te6 octahedra, and edges with two equivalent Bi(6)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-6°. In the second Sn site, Sn(2) is bonded to one Te(13), one Te(14), two equivalent Te(10), and two equivalent Te(17) atoms to form distorted SnTe6 octahedra that share  a cornercorner with one Sn(1)Te6 octahedra, corners with two equivalent Bi(10)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra,  an edgeedge with one Bi(10)Te6 octahedra, edges with two equivalent Sn(2)Te6 octahedra, edges with two equivalent Sn(3)Te6 octahedra, edges with two equivalent Sn(4)Te6 octahedra, and edges with two equivalent Bi(6)Te6 octahedra. The corner-sharing octahedral tilt angles range from 6-55°. In the third Sn site, Sn(3) is bonded to one Te(17), one Te(8), two equivalent Te(12), and two equivalent Te(13) atoms to form SnTe6 octahedra that share  a cornercorner with one Sn(4)Te6 octahedra,  a cornercorner with one Bi(4)Te6 octahedra, corners with two equivalent Bi(6)Te6 octahedra, corners with two equivalent Bi(8)Te6 octahedra,  an edgeedge with one Bi(6)Te6 octahedra,  an edgeedge with one Bi(8)Te6 octahedra, edges with two equivalent Sn(1)Te6 octahedra, edges with two equivalent Sn(2)Te6 octahedra, edges with two equivalent Sn(3)Te6 octahedra, edges with two equivalent Bi(10)Te6 octahedra, and edges with two equivalent Bi(7)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-8°. In the fourth Sn site, Sn(4) is bonded to one Te(1), one Te(17), two equivalent Te(14), and two equivalent Te(19) atoms to form SnTe6 octahedra that share  a cornercorner with one Sn(3)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra, edges with two equivalent Sn(2)Te6 octahedra, edges with two equivalent Sn(4)Te6 octahedra, edges with two equivalent Bi(1)Te6 octahedra, edges with two equivalent Bi(10)Te6 octahedra, and  a faceface with one Bi(9)Te6 octahedra. The corner-sharing octahedral tilt angles range from 8-48°. In the fifth Sn site, Sn(5) is bonded to one Te(18), one Te(2), two equivalent Te(16), and two equivalent Te(20) atoms to form SnTe6 octahedra that share  a cornercorner with one Bi(5)Te6 octahedra, corners with two equivalent Bi(10)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra,  an edgeedge with one Bi(10)Te6 octahedra, edges with two equivalent Sn(5)Te6 octahedra, edges with two equivalent Bi(2)Te6 octahedra, edges with two equivalent Bi(8)Te6 octahedra, and  a faceface with one Bi(9)Te6 octahedra. The corner-sharing octahedral tilt angles range from 3-48°. There are ten inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one Te(19), one Te(3), two equivalent Te(1), and two equivalent Te(5) atoms to form BiTe6 octahedra that share  a cornercorner with one Bi(10)Te6 octahedra, corners with two equivalent Bi(5)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra,  an edgeedge with one Bi(5)Te6 octahedra, edges with two equivalent Sn(4)Te6 octahedra, edges with two equivalent Bi(1)Te6 octahedra, and edges with two equivalent Bi(3)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-50°. In the second Bi site, Bi(2) is bonded to one Te(20), one Te(4), two equivalent Te(2), and two equivalent Te(7) atoms to form BiTe6 octahedra that share  a cornercorner with one Sn(1)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra, edges with two equivalent Sn(5)Te6 octahedra, edges with two equivalent Bi(2)Te6 octahedra, edges with two equivalent Bi(4)Te6 octahedra, and edges with two equivalent Bi(5)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-49°. In the third Bi site, Bi(3) is bonded to one Te(5), one Te(6), two equivalent Te(3), and two equivalent Te(9) atoms to form BiTe6 octahedra that share corners with two equivalent Sn(1)Te6 octahedra,  an edgeedge with one Sn(1)Te6 octahedra, edges with two equivalent Bi(1)Te6 octahedra, edges with two equivalent Bi(3)Te6 octahedra, edges with two equivalent Bi(5)Te6 octahedra, and edges with two equivalent Bi(6)Te6 octahedra. The corner-sharing octahedral tilt angles are 3°. In the fourth Bi site, Bi(4) is bonded to one Te(7), one Te(8), two equivalent Te(11), and two equivalent Te(4) atoms to form BiTe6 octahedra that share  a cornercorner with one Sn(3)Te6 octahedra, corners with two equivalent Bi(5)Te6 octahedra,  an edgeedge with one Bi(5)Te6 octahedra, edges with two equivalent Sn(1)Te6 octahedra, edges with two equivalent Bi(2)Te6 octahedra, edges with two equivalent Bi(4)Te6 octahedra, and edges with two equivalent Bi(7)Te6 octahedra. The corner-sharing octahedral tilt angles range from 5-6°. In the fifth Bi site, Bi(5) is bonded to one Te(2), one Te(9), two equivalent Te(4), and two equivalent Te(5) atoms to form BiTe6 octahedra that share  a cornercorner with one Sn(5)Te6 octahedra,  a cornercorner with one Bi(6)Te6 octahedra, corners with two equivalent Bi(1)Te6 octahedra, corners with two equivalent Bi(4)Te6 octahedra,  an edgeedge with one Bi(1)Te6 octahedra,  an edgeedge with one Bi(4)Te6 octahedra, edges with two equivalent Sn(1)Te6 octahedra, edges with two equivalent Bi(2)Te6 octahedra, edges with two equivalent Bi(3)Te6 octahedra, and edges with two equivalent Bi(5)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-7°. In the sixth Bi site, Bi(6) is bonded to one Te(10), one Te(9), two equivalent Te(13), and two equivalent Te(6) atoms to form BiTe6 octahedra that share  a cornercorner with one Bi(5)Te6 octahedra, corners with two equivalent Sn(3)Te6 octahedra,  an edgeedge with one Sn(3)Te6 octahedra, edges with two equivalent Sn(1)Te6 octahedra, edges with two equivalent Sn(2)Te6 octahedra, edges with two equivalent Bi(3)Te6 octahedra, and edges with two equivalent Bi(6)Te6 octahedra. The corner-sharing octahedral tilt angles range from 5-6°. In the seventh Bi site, Bi(7) is bonded to one Te(11), one Te(12), two equivalent Te(15), and two equivalent Te(8) atoms to form BiTe6 octahedra that share  a cornercorner with one Bi(10)Te6 octahedra, corners with two equivalent Sn(1)Te6 octahedra,  an edgeedge with one Sn(1)Te6 octahedra, edges with two equivalent Sn(3)Te6 octahedra, edges with two equivalent Bi(4)Te6 octahedra, edges with two equivalent Bi(7)Te6 octahedra, and edges with two equivalent Bi(8)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-4°. In the eighth Bi site, Bi(8) is bonded to one Te(15), one Te(16), two equivalent Te(12), and two equivalent Te(18) atoms to form BiTe6 octahedra that share corners with two equivalent Sn(3)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra,  an edgeedge with one Sn(3)Te6 octahedra, edges with two equivalent Sn(5)Te6 octahedra, edges with two equivalent Bi(10)Te6 octahedra, edges with two equivalent Bi(7)Te6 octahedra, and edges with two equivalent Bi(8)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-47°. In the ninth Bi site, Bi(9) is bonded to one Te(1), one Te(18), two equivalent Te(14), and two equivalent Te(20) atoms to form BiTe6 octahedra that share corners with two equivalent Sn(2)Te6 octahedra, corners with two equivalent Sn(4)Te6 octahedra, corners with two equivalent Sn(5)Te6 octahedra, corners with two equivalent Bi(1)Te6 octahedra, corners with two equivalent Bi(2)Te6 octahedra, corners with two equivalent Bi(8)Te6 octahedra, edges with two equivalent Bi(9)Te6 octahedra,  a faceface with one Sn(4)Te6 octahedra, and  a faceface with one Sn(5)Te6 octahedra. The corner-sharing octahedral tilt angles range from 47-55°. In the tenth Bi site, Bi(10) is bonded to one Te(12), one Te(19), two equivalent Te(16), and two equivalent Te(17) atoms to form BiTe6 octahedra that share  a cornercorner with one Bi(1)Te6 octahedra,  a cornercorner with one Bi(7)Te6 octahedra, corners with two equivalent Sn(2)Te6 octahedra, corners with two equivalent Sn(5)Te6 octahedra,  an edgeedge with one Sn(2)Te6 octahedra,  an edgeedge with one Sn(5)Te6 octahedra, edges with two equivalent Sn(3)Te6 octahedra, edges with two equivalent Sn(4)Te6 octahedra, edges with two equivalent Bi(10)Te6 octahedra, and edges with two equivalent Bi(8)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-13°. There are twenty inequivalent Te sites. In the first Te site, Te(1) is bonded in a rectangular see-saw-like geometry to one Sn(4), one Bi(9), and two equivalent Bi(1) atoms. In the second Te site, Te(2) is bonded in a rectangular see-saw-like geometry to one Sn(5), one Bi(5), and two equivalent Bi(2) atoms. In the third Te site, Te(3) is bonded in a distorted T-shaped geometry to one Bi(1) and two equivalent Bi(3) atoms. In the fourth Te site, Te(4) is bonded to one Sn(1), one Bi(2), two equivalent Bi(4), and two equivalent Bi(5) atoms to form TeSnBi5 octahedra that share  a cornercorner with one Te(13)Sn4Bi2 octahedra, corners with two equivalent Te(5)Bi5 square pyramids,  a cornercorner with one Te(20)Sn2Bi3 trigonal bipyramid, edges with two equivalent Te(9)Sn2Bi4 octahedra, edges with two equivalent Te(8)Sn3Bi3 octahedra, edges with two equivalent Te(4)SnBi5 octahedra, and  an edgeedge with one Te(5)Bi5 square pyramid. The corner-sharing octahedral tilt angles are 1°. In the fifth Te site, Te(5) is bonded to one Bi(3), two equivalent Bi(1), and two equivalent Bi(5) atoms to form TeBi5 square pyramids that share corners with two equivalent Te(4)SnBi5 octahedra,  an edgeedge with one Te(4)SnBi5 octahedra, edges with two equivalent Te(9)Sn2Bi4 octahedra, and edges with two equivalent Te(5)Bi5 square pyramids. The corner-sharing octahedral tilt angles are 4°. In the sixth Te site, Te(6) is bonded in a distorted T-shaped geometry to one Bi(3) and two equivalent Bi(6) atoms. In the seventh Te site, Te(7) is bonded in a distorted T-shaped geometry to one Bi(4) and two equivalent Bi(2) atoms. In the eighth Te site, Te(8) is bonded to one Sn(3), two equivalent Sn(1), one Bi(4), and two equivalent Bi(7) atoms to form TeSn3Bi3 octahedra that share  a cornercorner with one Te(17)Sn4Bi2 octahedra, corners with two equivalent Te(9)Sn2Bi4 octahedra,  an edgeedge with one Te(9)Sn2Bi4 octahedra, edges with two equivalent Te(12)Sn2Bi4 octahedra, edges with two equivalent Te(8)Sn3Bi3 octahedra, edges with two equivalent Te(13)Sn4Bi2 octahedra, and edges with two equivalent Te(4)SnBi5 octahedra. The corner-sharing octahedral tilt angles range from 2-3°. In the ninth Te site, Te(9) is bonded to two equivalent Sn(1), one Bi(5), one Bi(6), and two equivalent Bi(3) atoms to form TeSn2Bi4 octahedra that share corners with two equivalent Te(8)Sn3Bi3 octahedra,  an edgeedge with one Te(8)Sn3Bi3 octahedra, edges with two equivalent Te(9)Sn2Bi4 octahedra, edges with two equivalent Te(13)Sn4Bi2 octahedra, edges with two equivalent Te(4)SnBi5 octahedra, and edges with two equivalent Te(5)Bi5 square pyramids. The corner-sharing octahedral tilt angles are 3°. In the tenth Te site, Te(10) is bonded in a distorted T-shaped geometry to two equivalent Sn(2) and one Bi(6) atom. In the eleventh Te site, Te(11) is bonded in a distorted T-shaped geometry to one Bi(7) and two equivalent Bi(4) atoms. In the twelfth Te site, Te(12) is bonded to two equivalent Sn(3), one Bi(10), one Bi(7), and two equivalent Bi(8) atoms to form TeSn2Bi4 octahedra that share corners with two equivalent Te(13)Sn4Bi2 octahedra,  an edgeedge with one Te(13)Sn4Bi2 octahedra, edges with two equivalent Te(12)Sn2Bi4 octahedra, edges with two equivalent Te(8)Sn3Bi3 octahedra, edges with two equivalent Te(17)Sn4Bi2 octahedra, and edges with two equivalent Te(16)Sn2Bi3 square pyramids. The corner-sharing octahedral tilt angles are 2°. In the thirteenth Te site, Te(13) is bonded to one Sn(1), one Sn(2), two equivalent Sn(3), and two equivalent Bi(6) atoms to form TeSn4Bi2 octahedra that share  a cornercorner with one Te(4)SnBi5 octahedra, corners with two equivalent Te(12)Sn2Bi4 octahedra,  an edgeedge with one Te(12)Sn2Bi4 octahedra, edges with two equivalent Te(9)Sn2Bi4 octahedra, edges with two equivalent Te(8)Sn3Bi3 octahedra, edges with two equivalent Te(13)Sn4Bi2 octahedra, and edges with two equivalent Te(17)Sn4Bi2 octahedra. The corner-sharing octahedral tilt angles range from 1-2°. In the fourteenth Te site, Te(14) is bonded in a 5-coordinate geometry to one Sn(2), two equivalent Sn(4), and two equivalent Bi(9) atoms. In the fifteenth Te site, Te(15) is bonded in a distorted T-shaped geometry to one Bi(8) and two equivalent Bi(7) atoms. In the sixteenth Te site, Te(16) is bonded to two equivalent Sn(5), one Bi(8), and two equivalent Bi(10) atoms to form TeSn2Bi3 square pyramids that share corners with two equivalent Te(17)Sn4Bi2 octahedra, corners with two equivalent Te(20)Sn2Bi3 trigonal bipyramids,  an edgeedge with one Te(17)Sn4Bi2 octahedra, edges with two equivalent Te(12)Sn2Bi4 octahedra, edges with two equivalent Te(16)Sn2Bi3 square pyramids, and  an edgeedge with one Te(20)Sn2Bi3 trigonal bipyramid. The corner-sharing octahedral tilt angles are 5°. In the seventeenth Te site, Te(17) is bonded to one Sn(3), one Sn(4), two equivalent Sn(2), and two equivalent Bi(10) atoms to form distorted TeSn4Bi2 octahedra that share  a cornercorner with one Te(8)Sn3Bi3 octahedra, corners with two equivalent Te(16)Sn2Bi3 square pyramids, edges with two equivalent Te(12)Sn2Bi4 octahedra, edges with two equivalent Te(13)Sn4Bi2 octahedra, edges with two equivalent Te(17)Sn4Bi2 octahedra, and  an edgeedge with one Te(16)Sn2Bi3 square pyramid. The corner-sharing octahedral tilt angles are 2°. In the eighteenth Te site, Te(18) is bonded in a rectangular see-saw-like geometry to one Sn(5), one Bi(9), and two equivalent Bi(8) atoms. In the nineteenth Te site, Te(19) is bonded in a rectangular see-saw-like geometry to two equivalent Sn(4), one Bi(1), and one Bi(10) atom. In the twentieth Te site, Te(20) is bonded to two equivalent Sn(5), one Bi(2), and two equivalent Bi(9) atoms to form distorted TeSn2Bi3 trigonal bipyramids that share  a cornercorner with one Te(4)SnBi5 octahedra, corners with two equivalent Te(16)Sn2Bi3 square pyramids,  an edgeedge with one Te(16)Sn2Bi3 square pyramid, and edges with two equivalent Te(20)Sn2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 8°.
SnBi2Te4 crystallizes in the monoclinic Cm space group. There are five inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one Te(13), one Te(4), two equivalent Te(8), and two equivalent Te(9) atoms to form SnTe6 octahedra that share  a cornercorner with one Sn(2)Te6 octahedra,  a cornercorner with one Bi(2)Te6 octahedra, corners with two equivalent Bi(3)Te6 octahedra, corners with two equivalent Bi(7)Te6 octahedra,  an edgeedge with one Bi(3)Te6 octahedra,  an edgeedge with one Bi(7)Te6 octahedra, edges with two equivalent Sn(1)Te6 octahedra, edges with two equivalent Sn(3)Te6 octahedra, edges with two equivalent Bi(4)Te6 octahedra, edges with two equivalent Bi(5)Te6 octahedra, and edges with two equivalent Bi(6)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-6°. The Sn(1)-Te(13) bond length is 3.12 Å. The Sn(1)-Te(4) bond length is 3.25 Å. Both Sn(1)-Te(8) bond lengths are 3.15 Å. Both Sn(1)-Te(9) bond lengths are 3.18 Å. In the second Sn site, Sn(2) is bonded to one Te(13), one Te(14), two equivalent Te(10), and two equivalent Te(17) atoms to form distorted SnTe6 octahedra that share  a cornercorner with one Sn(1)Te6 octahedra, corners with two equivalent Bi(10)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra,  an edgeedge with one Bi(10)Te6 octahedra, edges with two equivalent Sn(2)Te6 octahedra, edges with two equivalent Sn(3)Te6 octahedra, edges with two equivalent Sn(4)Te6 octahedra, and edges with two equivalent Bi(6)Te6 octahedra. The corner-sharing octahedral tilt angles range from 6-55°. The Sn(2)-Te(13) bond length is 3.24 Å. The Sn(2)-Te(14) bond length is 3.19 Å. Both Sn(2)-Te(10) bond lengths are 3.02 Å. Both Sn(2)-Te(17) bond lengths are 3.47 Å. In the third Sn site, Sn(3) is bonded to one Te(17), one Te(8), two equivalent Te(12), and two equivalent Te(13) atoms to form SnTe6 octahedra that share  a cornercorner with one Sn(4)Te6 octahedra,  a cornercorner with one Bi(4)Te6 octahedra, corners with two equivalent Bi(6)Te6 octahedra, corners with two equivalent Bi(8)Te6 octahedra,  an edgeedge with one Bi(6)Te6 octahedra,  an edgeedge with one Bi(8)Te6 octahedra, edges with two equivalent Sn(1)Te6 octahedra, edges with two equivalent Sn(2)Te6 octahedra, edges with two equivalent Sn(3)Te6 octahedra, edges with two equivalent Bi(10)Te6 octahedra, and edges with two equivalent Bi(7)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-8°. The Sn(3)-Te(17) bond length is 3.14 Å. The Sn(3)-Te(8) bond length is 3.19 Å. Both Sn(3)-Te(12) bond lengths are 3.24 Å. Both Sn(3)-Te(13) bond lengths are 3.14 Å. In the fourth Sn site, Sn(4) is bonded to one Te(1), one Te(17), two equivalent Te(14), and two equivalent Te(19) atoms to form SnTe6 octahedra that share  a cornercorner with one Sn(3)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra, edges with two equivalent Sn(2)Te6 octahedra, edges with two equivalent Sn(4)Te6 octahedra, edges with two equivalent Bi(1)Te6 octahedra, edges with two equivalent Bi(10)Te6 octahedra, and  a faceface with one Bi(9)Te6 octahedra. The corner-sharing octahedral tilt angles range from 8-48°. The Sn(4)-Te(1) bond length is 3.18 Å. The Sn(4)-Te(17) bond length is 3.32 Å. Both Sn(4)-Te(14) bond lengths are 3.41 Å. Both Sn(4)-Te(19) bond lengths are 3.05 Å. In the fifth Sn site, Sn(5) is bonded to one Te(18), one Te(2), two equivalent Te(16), and two equivalent Te(20) atoms to form SnTe6 octahedra that share  a cornercorner with one Bi(5)Te6 octahedra, corners with two equivalent Bi(10)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra,  an edgeedge with one Bi(10)Te6 octahedra, edges with two equivalent Sn(5)Te6 octahedra, edges with two equivalent Bi(2)Te6 octahedra, edges with two equivalent Bi(8)Te6 octahedra, and  a faceface with one Bi(9)Te6 octahedra. The corner-sharing octahedral tilt angles range from 3-48°. The Sn(5)-Te(18) bond length is 3.14 Å. The Sn(5)-Te(2) bond length is 3.27 Å. Both Sn(5)-Te(16) bond lengths are 3.19 Å. Both Sn(5)-Te(20) bond lengths are 3.15 Å. There are ten inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one Te(19), one Te(3), two equivalent Te(1), and two equivalent Te(5) atoms to form BiTe6 octahedra that share  a cornercorner with one Bi(10)Te6 octahedra, corners with two equivalent Bi(5)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra,  an edgeedge with one Bi(5)Te6 octahedra, edges with two equivalent Sn(4)Te6 octahedra, edges with two equivalent Bi(1)Te6 octahedra, and edges with two equivalent Bi(3)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-50°. The Bi(1)-Te(19) bond length is 3.39 Å. The Bi(1)-Te(3) bond length is 3.03 Å. Both Bi(1)-Te(1) bond lengths are 3.05 Å. Both Bi(1)-Te(5) bond lengths are 3.31 Å. In the second Bi site, Bi(2) is bonded to one Te(20), one Te(4), two equivalent Te(2), and two equivalent Te(7) atoms to form BiTe6 octahedra that share  a cornercorner with one Sn(1)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra, edges with two equivalent Sn(5)Te6 octahedra, edges with two equivalent Bi(2)Te6 octahedra, edges with two equivalent Bi(4)Te6 octahedra, and edges with two equivalent Bi(5)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-49°. The Bi(2)-Te(20) bond length is 3.20 Å. The Bi(2)-Te(4) bond length is 3.20 Å. Both Bi(2)-Te(2) bond lengths are 3.19 Å. Both Bi(2)-Te(7) bond lengths are 3.17 Å. In the third Bi site, Bi(3) is bonded to one Te(5), one Te(6), two equivalent Te(3), and two equivalent Te(9) atoms to form BiTe6 octahedra that share corners with two equivalent Sn(1)Te6 octahedra,  an edgeedge with one Sn(1)Te6 octahedra, edges with two equivalent Bi(1)Te6 octahedra, edges with two equivalent Bi(3)Te6 octahedra, edges with two equivalent Bi(5)Te6 octahedra, and edges with two equivalent Bi(6)Te6 octahedra. The corner-sharing octahedral tilt angles are 3°. The Bi(3)-Te(5) bond length is 3.24 Å. The Bi(3)-Te(6) bond length is 3.14 Å. Both Bi(3)-Te(3) bond lengths are 3.10 Å. Both Bi(3)-Te(9) bond lengths are 3.28 Å. In the fourth Bi site, Bi(4) is bonded to one Te(7), one Te(8), two equivalent Te(11), and two equivalent Te(4) atoms to form BiTe6 octahedra that share  a cornercorner with one Sn(3)Te6 octahedra, corners with two equivalent Bi(5)Te6 octahedra,  an edgeedge with one Bi(5)Te6 octahedra, edges with two equivalent Sn(1)Te6 octahedra, edges with two equivalent Bi(2)Te6 octahedra, edges with two equivalent Bi(4)Te6 octahedra, and edges with two equivalent Bi(7)Te6 octahedra. The corner-sharing octahedral tilt angles range from 5-6°. The Bi(4)-Te(7) bond length is 2.98 Å. The Bi(4)-Te(8) bond length is 3.40 Å. Both Bi(4)-Te(11) bond lengths are 3.06 Å. Both Bi(4)-Te(4) bond lengths are 3.42 Å. In the fifth Bi site, Bi(5) is bonded to one Te(2), one Te(9), two equivalent Te(4), and two equivalent Te(5) atoms to form BiTe6 octahedra that share  a cornercorner with one Sn(5)Te6 octahedra,  a cornercorner with one Bi(6)Te6 octahedra, corners with two equivalent Bi(1)Te6 octahedra, corners with two equivalent Bi(4)Te6 octahedra,  an edgeedge with one Bi(1)Te6 octahedra,  an edgeedge with one Bi(4)Te6 octahedra, edges with two equivalent Sn(1)Te6 octahedra, edges with two equivalent Bi(2)Te6 octahedra, edges with two equivalent Bi(3)Te6 octahedra, and edges with two equivalent Bi(5)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-7°. The Bi(5)-Te(2) bond length is 3.00 Å. The Bi(5)-Te(9) bond length is 3.29 Å. Both Bi(5)-Te(4) bond lengths are 3.20 Å. Both Bi(5)-Te(5) bond lengths are 3.18 Å. In the sixth Bi site, Bi(6) is bonded to one Te(10), one Te(9), two equivalent Te(13), and two equivalent Te(6) atoms to form BiTe6 octahedra that share  a cornercorner with one Bi(5)Te6 octahedra, corners with two equivalent Sn(3)Te6 octahedra,  an edgeedge with one Sn(3)Te6 octahedra, edges with two equivalent Sn(1)Te6 octahedra, edges with two equivalent Sn(2)Te6 octahedra, edges with two equivalent Bi(3)Te6 octahedra, and edges with two equivalent Bi(6)Te6 octahedra. The corner-sharing octahedral tilt angles range from 5-6°. The Bi(6)-Te(10) bond length is 3.01 Å. The Bi(6)-Te(9) bond length is 3.35 Å. Both Bi(6)-Te(13) bond lengths are 3.40 Å. Both Bi(6)-Te(6) bond lengths are 3.05 Å. In the seventh Bi site, Bi(7) is bonded to one Te(11), one Te(12), two equivalent Te(15), and two equivalent Te(8) atoms to form BiTe6 octahedra that share  a cornercorner with one Bi(10)Te6 octahedra, corners with two equivalent Sn(1)Te6 octahedra,  an edgeedge with one Sn(1)Te6 octahedra, edges with two equivalent Sn(3)Te6 octahedra, edges with two equivalent Bi(4)Te6 octahedra, edges with two equivalent Bi(7)Te6 octahedra, and edges with two equivalent Bi(8)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-4°. The Bi(7)-Te(11) bond length is 3.10 Å. The Bi(7)-Te(12) bond length is 3.32 Å. Both Bi(7)-Te(15) bond lengths are 3.05 Å. Both Bi(7)-Te(8) bond lengths are 3.36 Å. In the eighth Bi site, Bi(8) is bonded to one Te(15), one Te(16), two equivalent Te(12), and two equivalent Te(18) atoms to form BiTe6 octahedra that share corners with two equivalent Sn(3)Te6 octahedra, corners with two equivalent Bi(9)Te6 octahedra,  an edgeedge with one Sn(3)Te6 octahedra, edges with two equivalent Sn(5)Te6 octahedra, edges with two equivalent Bi(10)Te6 octahedra, edges with two equivalent Bi(7)Te6 octahedra, and edges with two equivalent Bi(8)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-47°. The Bi(8)-Te(15) bond length is 3.22 Å. The Bi(8)-Te(16) bond length is 3.15 Å. Both Bi(8)-Te(12) bond lengths are 3.21 Å. Both Bi(8)-Te(18) bond lengths are 3.13 Å. In the ninth Bi site, Bi(9) is bonded to one Te(1), one Te(18), two equivalent Te(14), and two equivalent Te(20) atoms to form BiTe6 octahedra that share corners with two equivalent Sn(2)Te6 octahedra, corners with two equivalent Sn(4)Te6 octahedra, corners with two equivalent Sn(5)Te6 octahedra, corners with two equivalent Bi(1)Te6 octahedra, corners with two equivalent Bi(2)Te6 octahedra, corners with two equivalent Bi(8)Te6 octahedra, edges with two equivalent Bi(9)Te6 octahedra,  a faceface with one Sn(4)Te6 octahedra, and  a faceface with one Sn(5)Te6 octahedra. The corner-sharing octahedral tilt angles range from 47-55°. The Bi(9)-Te(1) bond length is 3.29 Å. The Bi(9)-Te(18) bond length is 3.11 Å. Both Bi(9)-Te(14) bond lengths are 3.08 Å. Both Bi(9)-Te(20) bond lengths are 3.29 Å. In the tenth Bi site, Bi(10) is bonded to one Te(12), one Te(19), two equivalent Te(16), and two equivalent Te(17) atoms to form BiTe6 octahedra that share  a cornercorner with one Bi(1)Te6 octahedra,  a cornercorner with one Bi(7)Te6 octahedra, corners with two equivalent Sn(2)Te6 octahedra, corners with two equivalent Sn(5)Te6 octahedra,  an edgeedge with one Sn(2)Te6 octahedra,  an edgeedge with one Sn(5)Te6 octahedra, edges with two equivalent Sn(3)Te6 octahedra, edges with two equivalent Sn(4)Te6 octahedra, edges with two equivalent Bi(10)Te6 octahedra, and edges with two equivalent Bi(8)Te6 octahedra. The corner-sharing octahedral tilt angles range from 2-13°. The Bi(10)-Te(12) bond length is 3.32 Å. The Bi(10)-Te(19) bond length is 3.10 Å. Both Bi(10)-Te(16) bond lengths are 3.18 Å. Both Bi(10)-Te(17) bond lengths are 3.13 Å. There are twenty inequivalent Te sites. In the first Te site, Te(1) is bonded in a rectangular see-saw-like geometry to one Sn(4), one Bi(9), and two equivalent Bi(1) atoms. In the second Te site, Te(2) is bonded in a rectangular see-saw-like geometry to one Sn(5), one Bi(5), and two equivalent Bi(2) atoms. In the third Te site, Te(3) is bonded in a distorted T-shaped geometry to one Bi(1) and two equivalent Bi(3) atoms. In the fourth Te site, Te(4) is bonded to one Sn(1), one Bi(2), two equivalent Bi(4), and two equivalent Bi(5) atoms to form TeSnBi5 octahedra that share  a cornercorner with one Te(13)Sn4Bi2 octahedra, corners with two equivalent Te(5)Bi5 square pyramids,  a cornercorner with one Te(20)Sn2Bi3 trigonal bipyramid, edges with two equivalent Te(9)Sn2Bi4 octahedra, edges with two equivalent Te(8)Sn3Bi3 octahedra, edges with two equivalent Te(4)SnBi5 octahedra, and  an edgeedge with one Te(5)Bi5 square pyramid. The corner-sharing octahedral tilt angles are 1°. In the fifth Te site, Te(5) is bonded to one Bi(3), two equivalent Bi(1), and two equivalent Bi(5) atoms to form TeBi5 square pyramids that share corners with two equivalent Te(4)SnBi5 octahedra,  an edgeedge with one Te(4)SnBi5 octahedra, edges with two equivalent Te(9)Sn2Bi4 octahedra, and edges with two equivalent Te(5)Bi5 square pyramids. The corner-sharing octahedral tilt angles are 4°. In the sixth Te site, Te(6) is bonded in a distorted T-shaped geometry to one Bi(3) and two equivalent Bi(6) atoms. In the seventh Te site, Te(7) is bonded in a distorted T-shaped geometry to one Bi(4) and two equivalent Bi(2) atoms. In the eighth Te site, Te(8) is bonded to one Sn(3), two equivalent Sn(1), one Bi(4), and two equivalent Bi(7) atoms to form TeSn3Bi3 octahedra that share  a cornercorner with one Te(17)Sn4Bi2 octahedra, corners with two equivalent Te(9)Sn2Bi4 octahedra,  an edgeedge with one Te(9)Sn2Bi4 octahedra, edges with two equivalent Te(12)Sn2Bi4 octahedra, edges with two equivalent Te(8)Sn3Bi3 octahedra, edges with two equivalent Te(13)Sn4Bi2 octahedra, and edges with two equivalent Te(4)SnBi5 octahedra. The corner-sharing octahedral tilt angles range from 2-3°. In the ninth Te site, Te(9) is bonded to two equivalent Sn(1), one Bi(5), one Bi(6), and two equivalent Bi(3) atoms to form TeSn2Bi4 octahedra that share corners with two equivalent Te(8)Sn3Bi3 octahedra,  an edgeedge with one Te(8)Sn3Bi3 octahedra, edges with two equivalent Te(9)Sn2Bi4 octahedra, edges with two equivalent Te(13)Sn4Bi2 octahedra, edges with two equivalent Te(4)SnBi5 octahedra, and edges with two equivalent Te(5)Bi5 square pyramids. The corner-sharing octahedral tilt angles are 3°. In the tenth Te site, Te(10) is bonded in a distorted T-shaped geometry to two equivalent Sn(2) and one Bi(6) atom. In the eleventh Te site, Te(11) is bonded in a distorted T-shaped geometry to one Bi(7) and two equivalent Bi(4) atoms. In the twelfth Te site, Te(12) is bonded to two equivalent Sn(3), one Bi(10), one Bi(7), and two equivalent Bi(8) atoms to form TeSn2Bi4 octahedra that share corners with two equivalent Te(13)Sn4Bi2 octahedra,  an edgeedge with one Te(13)Sn4Bi2 octahedra, edges with two equivalent Te(12)Sn2Bi4 octahedra, edges with two equivalent Te(8)Sn3Bi3 octahedra, edges with two equivalent Te(17)Sn4Bi2 octahedra, and edges with two equivalent Te(16)Sn2Bi3 square pyramids. The corner-sharing octahedral tilt angles are 2°. In the thirteenth Te site, Te(13) is bonded to one Sn(1), one Sn(2), two equivalent Sn(3), and two equivalent Bi(6) atoms to form TeSn4Bi2 octahedra that share  a cornercorner with one Te(4)SnBi5 octahedra, corners with two equivalent Te(12)Sn2Bi4 octahedra,  an edgeedge with one Te(12)Sn2Bi4 octahedra, edges with two equivalent Te(9)Sn2Bi4 octahedra, edges with two equivalent Te(8)Sn3Bi3 octahedra, edges with two equivalent Te(13)Sn4Bi2 octahedra, and edges with two equivalent Te(17)Sn4Bi2 octahedra. The corner-sharing octahedral tilt angles range from 1-2°. In the fourteenth Te site, Te(14) is bonded in a 5-coordinate geometry to one Sn(2), two equivalent Sn(4), and two equivalent Bi(9) atoms. In the fifteenth Te site, Te(15) is bonded in a distorted T-shaped geometry to one Bi(8) and two equivalent Bi(7) atoms. In the sixteenth Te site, Te(16) is bonded to two equivalent Sn(5), one Bi(8), and two equivalent Bi(10) atoms to form TeSn2Bi3 square pyramids that share corners with two equivalent Te(17)Sn4Bi2 octahedra, corners with two equivalent Te(20)Sn2Bi3 trigonal bipyramids,  an edgeedge with one Te(17)Sn4Bi2 octahedra, edges with two equivalent Te(12)Sn2Bi4 octahedra, edges with two equivalent Te(16)Sn2Bi3 square pyramids, and  an edgeedge with one Te(20)Sn2Bi3 trigonal bipyramid. The corner-sharing octahedral tilt angles are 5°. In the seventeenth Te site, Te(17) is bonded to one Sn(3), one Sn(4), two equivalent Sn(2), and two equivalent Bi(10) atoms to form distorted TeSn4Bi2 octahedra that share  a cornercorner with one Te(8)Sn3Bi3 octahedra, corners with two equivalent Te(16)Sn2Bi3 square pyramids, edges with two equivalent Te(12)Sn2Bi4 octahedra, edges with two equivalent Te(13)Sn4Bi2 octahedra, edges with two equivalent Te(17)Sn4Bi2 octahedra, and  an edgeedge with one Te(16)Sn2Bi3 square pyramid. The corner-sharing octahedral tilt angles are 2°. In the eighteenth Te site, Te(18) is bonded in a rectangular see-saw-like geometry to one Sn(5), one Bi(9), and two equivalent Bi(8) atoms. In the nineteenth Te site, Te(19) is bonded in a rectangular see-saw-like geometry to two equivalent Sn(4), one Bi(1), and one Bi(10) atom. In the twentieth Te site, Te(20) is bonded to two equivalent Sn(5), one Bi(2), and two equivalent Bi(9) atoms to form distorted TeSn2Bi3 trigonal bipyramids that share  a cornercorner with one Te(4)SnBi5 octahedra, corners with two equivalent Te(16)Sn2Bi3 square pyramids,  an edgeedge with one Te(16)Sn2Bi3 square pyramid, and edges with two equivalent Te(20)Sn2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 8°.