KSr2Cl5 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(4) atoms. There are two inequivalent Sr sites. In the first Sr site, Sr(1) 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. In the second Sr site, Sr(2) is bonded to one Cl(2), one Cl(3), one Cl(4), two equivalent Cl(1), and two equivalent Cl(5) atoms to form distorted edge-sharing SrCl7 pentagonal bipyramids. There are five inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to two equivalent K(1) and two equivalent Sr(2) atoms to form distorted ClK2Sr2 tetrahedra that share corners with four equivalent Cl(4)K2Sr3 square pyramids, corners with two equivalent Cl(1)K2Sr2 tetrahedra, corners with four equivalent Cl(5)Sr4 tetrahedra, corners with two equivalent Cl(3)K2Sr3 trigonal bipyramids,  an edgeedge with one Cl(4)K2Sr3 square pyramid,  an edgeedge with one Cl(1)K2Sr2 tetrahedra, and edges with two equivalent Cl(3)K2Sr3 trigonal bipyramids. In the second Cl site, Cl(2) is bonded in a 5-coordinate geometry to two equivalent K(1), one Sr(2), and two equivalent Sr(1) atoms. In the third Cl site, Cl(3) is bonded to two equivalent K(1), one Sr(2), and two equivalent Sr(1) atoms to form ClK2Sr3 trigonal bipyramids that share corners with four equivalent Cl(4)K2Sr3 square pyramids, corners with two equivalent Cl(1)K2Sr2 tetrahedra, corners with two equivalent Cl(5)Sr4 tetrahedra, corners with four equivalent Cl(3)K2Sr3 trigonal bipyramids,  an edgeedge with one Cl(4)K2Sr3 square pyramid, edges with two equivalent Cl(1)K2Sr2 tetrahedra, edges with two equivalent Cl(5)Sr4 tetrahedra, and  a faceface with one Cl(4)K2Sr3 square pyramid. In the fourth Cl site, Cl(4) is bonded to two equivalent K(1), one Sr(2), and two equivalent Sr(1) atoms to form ClK2Sr3 square pyramids that share corners with four equivalent Cl(1)K2Sr2 tetrahedra, corners with four equivalent Cl(5)Sr4 tetrahedra, corners with four equivalent Cl(3)K2Sr3 trigonal bipyramids, edges with two equivalent Cl(4)K2Sr3 square pyramids,  an edgeedge with one Cl(1)K2Sr2 tetrahedra,  an edgeedge with one Cl(5)Sr4 tetrahedra,  an edgeedge with one Cl(3)K2Sr3 trigonal bipyramid, and  a faceface with one Cl(3)K2Sr3 trigonal bipyramid. In the fifth Cl site, Cl(5) is bonded to two equivalent Sr(1) and two equivalent Sr(2) atoms to form ClSr4 tetrahedra that share corners with four equivalent Cl(4)K2Sr3 square pyramids, corners with two equivalent Cl(5)Sr4 tetrahedra, corners with four equivalent Cl(1)K2Sr2 tetrahedra, corners with two equivalent Cl(3)K2Sr3 trigonal bipyramids,  an edgeedge with one Cl(4)K2Sr3 square pyramid,  an edgeedge with one Cl(5)Sr4 tetrahedra, and edges with two equivalent Cl(3)K2Sr3 trigonal bipyramids.
KSr2Cl5 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(4) atoms. There is one shorter (3.11 Å) and one longer (3.19 Å) K(1)-Cl(1) bond length. There is one shorter (3.36 Å) and one longer (3.57 Å) K(1)-Cl(2) bond length. Both K(1)-Cl(3) bond lengths are 3.29 Å. There is one shorter (3.29 Å) and one longer (3.37 Å) K(1)-Cl(4) bond length. There are two inequivalent Sr sites. In the first Sr site, Sr(1) 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 (3.02 Å) and one longer (3.11 Å) Sr(1)-Cl(2) bond length. There is one shorter (2.99 Å) and one longer (3.06 Å) Sr(1)-Cl(3) bond length. There is one shorter (3.00 Å) and one longer (3.01 Å) Sr(1)-Cl(4) bond length. There is one shorter (3.03 Å) and one longer (3.05 Å) Sr(1)-Cl(5) bond length. In the second Sr site, Sr(2) is bonded to one Cl(2), one Cl(3), one Cl(4), two equivalent Cl(1), and two equivalent Cl(5) atoms to form distorted edge-sharing SrCl7 pentagonal bipyramids. The Sr(2)-Cl(2) bond length is 2.95 Å. The Sr(2)-Cl(3) bond length is 3.00 Å. The Sr(2)-Cl(4) bond length is 3.05 Å. There is one shorter (2.86 Å) and one longer (2.92 Å) Sr(2)-Cl(1) bond length. There is one shorter (2.93 Å) and one longer (2.94 Å) Sr(2)-Cl(5) bond length. There are five inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to two equivalent K(1) and two equivalent Sr(2) atoms to form distorted ClK2Sr2 tetrahedra that share corners with four equivalent Cl(4)K2Sr3 square pyramids, corners with two equivalent Cl(1)K2Sr2 tetrahedra, corners with four equivalent Cl(5)Sr4 tetrahedra, corners with two equivalent Cl(3)K2Sr3 trigonal bipyramids,  an edgeedge with one Cl(4)K2Sr3 square pyramid,  an edgeedge with one Cl(1)K2Sr2 tetrahedra, and edges with two equivalent Cl(3)K2Sr3 trigonal bipyramids. In the second Cl site, Cl(2) is bonded in a 5-coordinate geometry to two equivalent K(1), one Sr(2), and two equivalent Sr(1) atoms. In the third Cl site, Cl(3) is bonded to two equivalent K(1), one Sr(2), and two equivalent Sr(1) atoms to form ClK2Sr3 trigonal bipyramids that share corners with four equivalent Cl(4)K2Sr3 square pyramids, corners with two equivalent Cl(1)K2Sr2 tetrahedra, corners with two equivalent Cl(5)Sr4 tetrahedra, corners with four equivalent Cl(3)K2Sr3 trigonal bipyramids,  an edgeedge with one Cl(4)K2Sr3 square pyramid, edges with two equivalent Cl(1)K2Sr2 tetrahedra, edges with two equivalent Cl(5)Sr4 tetrahedra, and  a faceface with one Cl(4)K2Sr3 square pyramid. In the fourth Cl site, Cl(4) is bonded to two equivalent K(1), one Sr(2), and two equivalent Sr(1) atoms to form ClK2Sr3 square pyramids that share corners with four equivalent Cl(1)K2Sr2 tetrahedra, corners with four equivalent Cl(5)Sr4 tetrahedra, corners with four equivalent Cl(3)K2Sr3 trigonal bipyramids, edges with two equivalent Cl(4)K2Sr3 square pyramids,  an edgeedge with one Cl(1)K2Sr2 tetrahedra,  an edgeedge with one Cl(5)Sr4 tetrahedra,  an edgeedge with one Cl(3)K2Sr3 trigonal bipyramid, and  a faceface with one Cl(3)K2Sr3 trigonal bipyramid. In the fifth Cl site, Cl(5) is bonded to two equivalent Sr(1) and two equivalent Sr(2) atoms to form ClSr4 tetrahedra that share corners with four equivalent Cl(4)K2Sr3 square pyramids, corners with two equivalent Cl(5)Sr4 tetrahedra, corners with four equivalent Cl(1)K2Sr2 tetrahedra, corners with two equivalent Cl(3)K2Sr3 trigonal bipyramids,  an edgeedge with one Cl(4)K2Sr3 square pyramid,  an edgeedge with one Cl(5)Sr4 tetrahedra, and edges with two equivalent Cl(3)K2Sr3 trigonal bipyramids.