K2PrI5 crystallizes in the orthorhombic Pnma space group. K(1) is bonded in a 8-coordinate geometry to two equivalent I(1), two equivalent I(2), two equivalent I(3), and two equivalent I(4) atoms. Pr(1) is bonded to one I(1), one I(3), one I(4), and four equivalent I(2) atoms to form distorted edge-sharing PrI7 pentagonal bipyramids. There are four inequivalent I sites. In the first I site, I(1) is bonded to four equivalent K(1) and one Pr(1) atom to form IK4Pr trigonal bipyramids that share corners with four equivalent I(3)K4Pr trigonal bipyramids, corners with five equivalent I(4)K4Pr trigonal bipyramids, corners with eight equivalent I(2)K2Pr2 trigonal pyramids,  an edgeedge with one I(3)K4Pr trigonal bipyramid, edges with two equivalent I(1)K4Pr trigonal bipyramids, edges with two equivalent I(4)K4Pr trigonal bipyramids, edges with two equivalent I(2)K2Pr2 trigonal pyramids, and  a faceface with one I(3)K4Pr trigonal bipyramid. In the second I site, I(2) is bonded to two equivalent K(1) and two equivalent Pr(1) atoms to form distorted IK2Pr2 trigonal pyramids that share corners with two equivalent I(3)K4Pr trigonal bipyramids, corners with two equivalent I(4)K4Pr trigonal bipyramids, corners with four equivalent I(1)K4Pr trigonal bipyramids, corners with six equivalent I(2)K2Pr2 trigonal pyramids,  an edgeedge with one I(1)K4Pr trigonal bipyramid, edges with two equivalent I(3)K4Pr trigonal bipyramids, edges with two equivalent I(4)K4Pr trigonal bipyramids, and  an edgeedge with one I(2)K2Pr2 trigonal pyramid. In the third I site, I(3) is bonded to four equivalent K(1) and one Pr(1) atom to form IK4Pr trigonal bipyramids that share  a cornercorner with one I(4)K4Pr trigonal bipyramid, corners with four equivalent I(1)K4Pr trigonal bipyramids, corners with four equivalent I(3)K4Pr trigonal bipyramids, corners with four equivalent I(2)K2Pr2 trigonal pyramids,  an edgeedge with one I(1)K4Pr trigonal bipyramid, edges with four equivalent I(4)K4Pr trigonal bipyramids, edges with four equivalent I(2)K2Pr2 trigonal pyramids, and  a faceface with one I(1)K4Pr trigonal bipyramid. In the fourth I site, I(4) is bonded to four equivalent K(1) and one Pr(1) atom to form distorted IK4Pr trigonal bipyramids that share  a cornercorner with one I(3)K4Pr trigonal bipyramid, corners with four equivalent I(4)K4Pr trigonal bipyramids, corners with five equivalent I(1)K4Pr trigonal bipyramids, corners with four equivalent I(2)K2Pr2 trigonal pyramids, edges with two equivalent I(1)K4Pr trigonal bipyramids, edges with four equivalent I(3)K4Pr trigonal bipyramids, and edges with four equivalent I(2)K2Pr2 trigonal pyramids.
K2PrI5 crystallizes in the orthorhombic Pnma space group. K(1) is bonded in a 8-coordinate geometry to two equivalent I(1), two equivalent I(2), two equivalent I(3), and two equivalent I(4) atoms. There is one shorter (3.61 Å) and one longer (3.62 Å) K(1)-I(1) bond length. There is one shorter (3.79 Å) and one longer (3.91 Å) K(1)-I(2) bond length. There is one shorter (3.61 Å) and one longer (3.62 Å) K(1)-I(3) bond length. There is one shorter (3.68 Å) and one longer (3.77 Å) K(1)-I(4) bond length. Pr(1) is bonded to one I(1), one I(3), one I(4), and four equivalent I(2) atoms to form distorted edge-sharing PrI7 pentagonal bipyramids. The Pr(1)-I(1) bond length is 3.25 Å. The Pr(1)-I(3) bond length is 3.19 Å. The Pr(1)-I(4) bond length is 3.21 Å. There are two shorter (3.21 Å) and two longer (3.30 Å) Pr(1)-I(2) bond lengths. There are four inequivalent I sites. In the first I site, I(1) is bonded to four equivalent K(1) and one Pr(1) atom to form IK4Pr trigonal bipyramids that share corners with four equivalent I(3)K4Pr trigonal bipyramids, corners with five equivalent I(4)K4Pr trigonal bipyramids, corners with eight equivalent I(2)K2Pr2 trigonal pyramids,  an edgeedge with one I(3)K4Pr trigonal bipyramid, edges with two equivalent I(1)K4Pr trigonal bipyramids, edges with two equivalent I(4)K4Pr trigonal bipyramids, edges with two equivalent I(2)K2Pr2 trigonal pyramids, and  a faceface with one I(3)K4Pr trigonal bipyramid. In the second I site, I(2) is bonded to two equivalent K(1) and two equivalent Pr(1) atoms to form distorted IK2Pr2 trigonal pyramids that share corners with two equivalent I(3)K4Pr trigonal bipyramids, corners with two equivalent I(4)K4Pr trigonal bipyramids, corners with four equivalent I(1)K4Pr trigonal bipyramids, corners with six equivalent I(2)K2Pr2 trigonal pyramids,  an edgeedge with one I(1)K4Pr trigonal bipyramid, edges with two equivalent I(3)K4Pr trigonal bipyramids, edges with two equivalent I(4)K4Pr trigonal bipyramids, and  an edgeedge with one I(2)K2Pr2 trigonal pyramid. In the third I site, I(3) is bonded to four equivalent K(1) and one Pr(1) atom to form IK4Pr trigonal bipyramids that share  a cornercorner with one I(4)K4Pr trigonal bipyramid, corners with four equivalent I(1)K4Pr trigonal bipyramids, corners with four equivalent I(3)K4Pr trigonal bipyramids, corners with four equivalent I(2)K2Pr2 trigonal pyramids,  an edgeedge with one I(1)K4Pr trigonal bipyramid, edges with four equivalent I(4)K4Pr trigonal bipyramids, edges with four equivalent I(2)K2Pr2 trigonal pyramids, and  a faceface with one I(1)K4Pr trigonal bipyramid. In the fourth I site, I(4) is bonded to four equivalent K(1) and one Pr(1) atom to form distorted IK4Pr trigonal bipyramids that share  a cornercorner with one I(3)K4Pr trigonal bipyramid, corners with four equivalent I(4)K4Pr trigonal bipyramids, corners with five equivalent I(1)K4Pr trigonal bipyramids, corners with four equivalent I(2)K2Pr2 trigonal pyramids, edges with two equivalent I(1)K4Pr trigonal bipyramids, edges with four equivalent I(3)K4Pr trigonal bipyramids, and edges with four equivalent I(2)K2Pr2 trigonal pyramids.