RbPr6(CI6)2 crystallizes in the triclinic P-1 space group. Rb(1) is bonded in a distorted square co-planar geometry to two equivalent I(2) and two equivalent I(3) atoms. There are three inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to two equivalent C(1), one I(1), one I(3), one I(4), and two equivalent I(6) atoms to form distorted PrC2I5 pentagonal bipyramids that share  a cornercorner with one Pr(2)CI5 octahedra,  a cornercorner with one Pr(3)C2I5 pentagonal bipyramid, edges with two equivalent Pr(2)CI5 octahedra, edges with two equivalent Pr(1)C2I5 pentagonal bipyramids, and faces with two equivalent Pr(3)C2I5 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 2°. In the second Pr site, Pr(2) is bonded to one C(1), one I(3), one I(5), one I(6), and two equivalent I(2) atoms to form distorted PrCI5 octahedra that share  a cornercorner with one Pr(1)C2I5 pentagonal bipyramid,  a cornercorner with one Pr(3)C2I5 pentagonal bipyramid,  an edgeedge with one Pr(2)CI5 octahedra, edges with two equivalent Pr(1)C2I5 pentagonal bipyramids, and edges with two equivalent Pr(3)C2I5 pentagonal bipyramids. In the third Pr site, Pr(3) is bonded to two equivalent C(1), one I(2), one I(4), one I(5), and two equivalent I(1) atoms to form distorted PrC2I5 pentagonal bipyramids that share  a cornercorner with one Pr(2)CI5 octahedra,  a cornercorner with one Pr(1)C2I5 pentagonal bipyramid, edges with two equivalent Pr(2)CI5 octahedra, edges with two equivalent Pr(3)C2I5 pentagonal bipyramids, and faces with two equivalent Pr(1)C2I5 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 12°. C(1) is bonded in a 6-coordinate geometry to one Pr(2), two equivalent Pr(1), two equivalent Pr(3), and one C(1) atom. There are six inequivalent I sites. In the first I site, I(1) is bonded in a 3-coordinate geometry to one Pr(1) and two equivalent Pr(3) atoms. In the second I site, I(2) is bonded in a distorted rectangular see-saw-like geometry to one Rb(1), one Pr(3), and two equivalent Pr(2) atoms. In the third I site, I(3) is bonded in a 3-coordinate geometry to one Rb(1), one Pr(1), and one Pr(2) atom. In the fourth I site, I(4) is bonded in a 2-coordinate geometry to one Pr(1) and one Pr(3) atom. In the fifth I site, I(5) is bonded in a distorted L-shaped geometry to one Pr(2) and one Pr(3) atom. In the sixth I site, I(6) is bonded in a distorted T-shaped geometry to one Pr(2) and two equivalent Pr(1) atoms.
RbPr6(CI6)2 crystallizes in the triclinic P-1 space group. Rb(1) is bonded in a distorted square co-planar geometry to two equivalent I(2) and two equivalent I(3) atoms. Both Rb(1)-I(2) bond lengths are 4.22 Å. Both Rb(1)-I(3) bond lengths are 4.08 Å. There are three inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to two equivalent C(1), one I(1), one I(3), one I(4), and two equivalent I(6) atoms to form distorted PrC2I5 pentagonal bipyramids that share  a cornercorner with one Pr(2)CI5 octahedra,  a cornercorner with one Pr(3)C2I5 pentagonal bipyramid, edges with two equivalent Pr(2)CI5 octahedra, edges with two equivalent Pr(1)C2I5 pentagonal bipyramids, and faces with two equivalent Pr(3)C2I5 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 2°. There is one shorter (2.68 Å) and one longer (2.69 Å) Pr(1)-C(1) bond length. The Pr(1)-I(1) bond length is 3.22 Å. The Pr(1)-I(3) bond length is 3.20 Å. The Pr(1)-I(4) bond length is 3.13 Å. There is one shorter (3.25 Å) and one longer (3.48 Å) Pr(1)-I(6) bond length. In the second Pr site, Pr(2) is bonded to one C(1), one I(3), one I(5), one I(6), and two equivalent I(2) atoms to form distorted PrCI5 octahedra that share  a cornercorner with one Pr(1)C2I5 pentagonal bipyramid,  a cornercorner with one Pr(3)C2I5 pentagonal bipyramid,  an edgeedge with one Pr(2)CI5 octahedra, edges with two equivalent Pr(1)C2I5 pentagonal bipyramids, and edges with two equivalent Pr(3)C2I5 pentagonal bipyramids. The Pr(2)-C(1) bond length is 2.36 Å. The Pr(2)-I(3) bond length is 3.15 Å. The Pr(2)-I(5) bond length is 3.13 Å. The Pr(2)-I(6) bond length is 3.25 Å. There is one shorter (3.24 Å) and one longer (3.49 Å) Pr(2)-I(2) bond length. In the third Pr site, Pr(3) is bonded to two equivalent C(1), one I(2), one I(4), one I(5), and two equivalent I(1) atoms to form distorted PrC2I5 pentagonal bipyramids that share  a cornercorner with one Pr(2)CI5 octahedra,  a cornercorner with one Pr(1)C2I5 pentagonal bipyramid, edges with two equivalent Pr(2)CI5 octahedra, edges with two equivalent Pr(3)C2I5 pentagonal bipyramids, and faces with two equivalent Pr(1)C2I5 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 12°. There is one shorter (2.67 Å) and one longer (2.68 Å) Pr(3)-C(1) bond length. The Pr(3)-I(2) bond length is 3.31 Å. The Pr(3)-I(4) bond length is 3.12 Å. The Pr(3)-I(5) bond length is 3.19 Å. There is one shorter (3.20 Å) and one longer (3.53 Å) Pr(3)-I(1) bond length. C(1) is bonded in a 6-coordinate geometry to one Pr(2), two equivalent Pr(1), two equivalent Pr(3), and one C(1) atom. The C(1)-C(1) bond length is 1.41 Å. There are six inequivalent I sites. In the first I site, I(1) is bonded in a 3-coordinate geometry to one Pr(1) and two equivalent Pr(3) atoms. In the second I site, I(2) is bonded in a distorted rectangular see-saw-like geometry to one Rb(1), one Pr(3), and two equivalent Pr(2) atoms. In the third I site, I(3) is bonded in a 3-coordinate geometry to one Rb(1), one Pr(1), and one Pr(2) atom. In the fourth I site, I(4) is bonded in a 2-coordinate geometry to one Pr(1) and one Pr(3) atom. In the fifth I site, I(5) is bonded in a distorted L-shaped geometry to one Pr(2) and one Pr(3) atom. In the sixth I site, I(6) is bonded in a distorted T-shaped geometry to one Pr(2) and two equivalent Pr(1) atoms.