Sm6Cd(SiS7)2 crystallizes in the trigonal P3 space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 8-coordinate geometry to one S(1), one S(6), two equivalent S(3), two equivalent S(4), and two equivalent S(5) atoms. In the second Sm site, Sm(2) is bonded in a 8-coordinate geometry to one S(2), one S(5), two equivalent S(3), two equivalent S(4), and two equivalent S(6) atoms. Cd(1) is bonded in an octahedral geometry to three equivalent S(3) and three equivalent S(4) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one S(1) and three equivalent S(5) atoms. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one S(2) and three equivalent S(6) atoms. There are six inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Sm(1) and one Si(1) atom to form distorted corner-sharing SSm3Si tetrahedra. In the second S site, S(2) is bonded to three equivalent Sm(2) and one Si(2) atom to form distorted corner-sharing SSm3Si tetrahedra. In the third S site, S(3) is bonded to two equivalent Sm(1), two equivalent Sm(2), and one Cd(1) atom to form distorted SSm4Cd trigonal bipyramids that share corners with two equivalent S(1)Sm3Si tetrahedra, corners with two equivalent S(2)Sm3Si tetrahedra,  a cornercorner with one S(4)Sm4Cd trigonal bipyramid, corners with two equivalent S(3)Sm4Cd trigonal bipyramids, edges with two equivalent S(3)Sm4Cd trigonal bipyramids, edges with two equivalent S(4)Sm4Cd trigonal bipyramids, and faces with two equivalent S(4)Sm4Cd trigonal bipyramids. In the fourth S site, S(4) is bonded to two equivalent Sm(1), two equivalent Sm(2), and one Cd(1) atom to form distorted SSm4Cd trigonal bipyramids that share corners with two equivalent S(1)Sm3Si tetrahedra, corners with two equivalent S(2)Sm3Si tetrahedra,  a cornercorner with one S(3)Sm4Cd trigonal bipyramid, corners with two equivalent S(4)Sm4Cd trigonal bipyramids, edges with two equivalent S(3)Sm4Cd trigonal bipyramids, edges with two equivalent S(4)Sm4Cd trigonal bipyramids, and faces with two equivalent S(3)Sm4Cd trigonal bipyramids. In the fifth S site, S(5) is bonded in a distorted rectangular see-saw-like geometry to one Sm(2), two equivalent Sm(1), and one Si(1) atom. In the sixth S site, S(6) is bonded in a distorted rectangular see-saw-like geometry to one Sm(1), two equivalent Sm(2), and one Si(2) atom.
Sm6Cd(SiS7)2 crystallizes in the trigonal P3 space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 8-coordinate geometry to one S(1), one S(6), two equivalent S(3), two equivalent S(4), and two equivalent S(5) atoms. The Sm(1)-S(1) bond length is 3.04 Å. The Sm(1)-S(6) bond length is 3.01 Å. There is one shorter (2.89 Å) and one longer (3.07 Å) Sm(1)-S(3) bond length. There is one shorter (2.84 Å) and one longer (2.88 Å) Sm(1)-S(4) bond length. There is one shorter (2.85 Å) and one longer (2.95 Å) Sm(1)-S(5) bond length. In the second Sm site, Sm(2) is bonded in a 8-coordinate geometry to one S(2), one S(5), two equivalent S(3), two equivalent S(4), and two equivalent S(6) atoms. The Sm(2)-S(2) bond length is 3.04 Å. The Sm(2)-S(5) bond length is 3.00 Å. There is one shorter (2.86 Å) and one longer (2.87 Å) Sm(2)-S(3) bond length. There is one shorter (2.93 Å) and one longer (3.03 Å) Sm(2)-S(4) bond length. There is one shorter (2.85 Å) and one longer (2.95 Å) Sm(2)-S(6) bond length. Cd(1) is bonded in an octahedral geometry to three equivalent S(3) and three equivalent S(4) atoms. All Cd(1)-S(3) bond lengths are 2.68 Å. All Cd(1)-S(4) bond lengths are 2.71 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one S(1) and three equivalent S(5) atoms. The Si(1)-S(1) bond length is 2.10 Å. All Si(1)-S(5) bond lengths are 2.15 Å. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one S(2) and three equivalent S(6) atoms. The Si(2)-S(2) bond length is 2.11 Å. All Si(2)-S(6) bond lengths are 2.15 Å. There are six inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Sm(1) and one Si(1) atom to form distorted corner-sharing SSm3Si tetrahedra. In the second S site, S(2) is bonded to three equivalent Sm(2) and one Si(2) atom to form distorted corner-sharing SSm3Si tetrahedra. In the third S site, S(3) is bonded to two equivalent Sm(1), two equivalent Sm(2), and one Cd(1) atom to form distorted SSm4Cd trigonal bipyramids that share corners with two equivalent S(1)Sm3Si tetrahedra, corners with two equivalent S(2)Sm3Si tetrahedra,  a cornercorner with one S(4)Sm4Cd trigonal bipyramid, corners with two equivalent S(3)Sm4Cd trigonal bipyramids, edges with two equivalent S(3)Sm4Cd trigonal bipyramids, edges with two equivalent S(4)Sm4Cd trigonal bipyramids, and faces with two equivalent S(4)Sm4Cd trigonal bipyramids. In the fourth S site, S(4) is bonded to two equivalent Sm(1), two equivalent Sm(2), and one Cd(1) atom to form distorted SSm4Cd trigonal bipyramids that share corners with two equivalent S(1)Sm3Si tetrahedra, corners with two equivalent S(2)Sm3Si tetrahedra,  a cornercorner with one S(3)Sm4Cd trigonal bipyramid, corners with two equivalent S(4)Sm4Cd trigonal bipyramids, edges with two equivalent S(3)Sm4Cd trigonal bipyramids, edges with two equivalent S(4)Sm4Cd trigonal bipyramids, and faces with two equivalent S(3)Sm4Cd trigonal bipyramids. In the fifth S site, S(5) is bonded in a distorted rectangular see-saw-like geometry to one Sm(2), two equivalent Sm(1), and one Si(1) atom. In the sixth S site, S(6) is bonded in a distorted rectangular see-saw-like geometry to one Sm(1), two equivalent Sm(2), and one Si(2) atom.