KSm2Cl5 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 8-coordinate geometry to two equivalent Cl(1), two equivalent Cl(2), two equivalent Cl(3), and two equivalent Cl(5) atoms. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 7-coordinate geometry to one Cl(2), one Cl(3), one Cl(5), two equivalent Cl(1), and two equivalent Cl(4) atoms. In the second Sm site, Sm(2) is bonded in a 8-coordinate geometry to two equivalent Cl(2), two equivalent Cl(3), two equivalent Cl(4), and two equivalent Cl(5) atoms. There are five inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a 4-coordinate geometry to two equivalent K(1) and two equivalent Sm(1) atoms. In the second Cl site, Cl(2) is bonded to two equivalent K(1), one Sm(1), and two equivalent Sm(2) atoms to form distorted ClK2Sm3 square pyramids that share corners with four equivalent Cl(4)Sm4 tetrahedra, corners with four equivalent Cl(3)K2Sm3 trigonal bipyramids, edges with two equivalent Cl(2)K2Sm3 square pyramids,  an edgeedge with one Cl(4)Sm4 tetrahedra,  an edgeedge with one Cl(3)K2Sm3 trigonal bipyramid, and  a faceface with one Cl(3)K2Sm3 trigonal bipyramid. In the third Cl site, Cl(3) is bonded to two equivalent K(1), one Sm(1), and two equivalent Sm(2) atoms to form distorted ClK2Sm3 trigonal bipyramids that share corners with four equivalent Cl(2)K2Sm3 square pyramids, corners with two equivalent Cl(4)Sm4 tetrahedra, corners with four equivalent Cl(3)K2Sm3 trigonal bipyramids,  an edgeedge with one Cl(2)K2Sm3 square pyramid, edges with two equivalent Cl(4)Sm4 tetrahedra, and  a faceface with one Cl(2)K2Sm3 square pyramid. In the fourth Cl site, Cl(4) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form distorted ClSm4 tetrahedra that share corners with four equivalent Cl(2)K2Sm3 square pyramids, corners with two equivalent Cl(4)Sm4 tetrahedra, corners with two equivalent Cl(3)K2Sm3 trigonal bipyramids,  an edgeedge with one Cl(2)K2Sm3 square pyramid,  an edgeedge with one Cl(4)Sm4 tetrahedra, and edges with two equivalent Cl(3)K2Sm3 trigonal bipyramids. In the fifth Cl site, Cl(5) is bonded in a 5-coordinate geometry to two equivalent K(1), one Sm(1), and two equivalent Sm(2) atoms.
KSm2Cl5 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 8-coordinate geometry to two equivalent Cl(1), two equivalent Cl(2), two equivalent Cl(3), and two equivalent Cl(5) atoms. There is one shorter (2.98 Å) and one longer (3.52 Å) K(1)-Cl(1) bond length. There is one shorter (3.37 Å) and one longer (3.47 Å) K(1)-Cl(2) bond length. There is one shorter (3.08 Å) and one longer (3.24 Å) K(1)-Cl(3) bond length. There is one shorter (3.06 Å) and one longer (3.25 Å) K(1)-Cl(5) bond length. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 7-coordinate geometry to one Cl(2), one Cl(3), one Cl(5), two equivalent Cl(1), and two equivalent Cl(4) atoms. The Sm(1)-Cl(2) bond length is 3.01 Å. The Sm(1)-Cl(3) bond length is 2.90 Å. The Sm(1)-Cl(5) bond length is 2.82 Å. There is one shorter (2.93 Å) and one longer (3.12 Å) Sm(1)-Cl(1) bond length. There is one shorter (2.87 Å) and one longer (2.92 Å) Sm(1)-Cl(4) bond length. In the second Sm site, Sm(2) is bonded in a 8-coordinate geometry to two equivalent Cl(2), two equivalent Cl(3), two equivalent Cl(4), and two equivalent Cl(5) atoms. There is one shorter (2.85 Å) and one longer (2.92 Å) Sm(2)-Cl(2) bond length. There is one shorter (2.79 Å) and one longer (3.30 Å) Sm(2)-Cl(3) bond length. There is one shorter (2.85 Å) and one longer (2.95 Å) Sm(2)-Cl(4) bond length. There is one shorter (2.76 Å) and one longer (3.54 Å) Sm(2)-Cl(5) bond length. There are five inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a 4-coordinate geometry to two equivalent K(1) and two equivalent Sm(1) atoms. In the second Cl site, Cl(2) is bonded to two equivalent K(1), one Sm(1), and two equivalent Sm(2) atoms to form distorted ClK2Sm3 square pyramids that share corners with four equivalent Cl(4)Sm4 tetrahedra, corners with four equivalent Cl(3)K2Sm3 trigonal bipyramids, edges with two equivalent Cl(2)K2Sm3 square pyramids,  an edgeedge with one Cl(4)Sm4 tetrahedra,  an edgeedge with one Cl(3)K2Sm3 trigonal bipyramid, and  a faceface with one Cl(3)K2Sm3 trigonal bipyramid. In the third Cl site, Cl(3) is bonded to two equivalent K(1), one Sm(1), and two equivalent Sm(2) atoms to form distorted ClK2Sm3 trigonal bipyramids that share corners with four equivalent Cl(2)K2Sm3 square pyramids, corners with two equivalent Cl(4)Sm4 tetrahedra, corners with four equivalent Cl(3)K2Sm3 trigonal bipyramids,  an edgeedge with one Cl(2)K2Sm3 square pyramid, edges with two equivalent Cl(4)Sm4 tetrahedra, and  a faceface with one Cl(2)K2Sm3 square pyramid. In the fourth Cl site, Cl(4) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form distorted ClSm4 tetrahedra that share corners with four equivalent Cl(2)K2Sm3 square pyramids, corners with two equivalent Cl(4)Sm4 tetrahedra, corners with two equivalent Cl(3)K2Sm3 trigonal bipyramids,  an edgeedge with one Cl(2)K2Sm3 square pyramid,  an edgeedge with one Cl(4)Sm4 tetrahedra, and edges with two equivalent Cl(3)K2Sm3 trigonal bipyramids. In the fifth Cl site, Cl(5) is bonded in a 5-coordinate geometry to two equivalent K(1), one Sm(1), and two equivalent Sm(2) atoms.