CaPbI4 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to one I(3), one I(4), two equivalent I(1), and two equivalent I(2) atoms to form a mixture of corner and edge-sharing CaI6 octahedra. The corner-sharing octahedral tilt angles are 47°. Pb(1) is bonded in a rectangular see-saw-like geometry to one I(1), one I(2), one I(3), and one I(4) atom. There are four inequivalent I sites. In the first I site, I(1) is bonded in a distorted T-shaped geometry to two equivalent Ca(1) and one Pb(1) atom. In the second I site, I(2) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Pb(1) atom. In the third I site, I(3) is bonded in an L-shaped geometry to one Ca(1) and one Pb(1) atom. In the fourth I site, I(4) is bonded in a bent 120 degrees geometry to one Ca(1) and one Pb(1) atom.
CaPbI4 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to one I(3), one I(4), two equivalent I(1), and two equivalent I(2) atoms to form a mixture of corner and edge-sharing CaI6 octahedra. The corner-sharing octahedral tilt angles are 47°. The Ca(1)-I(3) bond length is 3.12 Å. The Ca(1)-I(4) bond length is 3.07 Å. There is one shorter (3.19 Å) and one longer (3.22 Å) Ca(1)-I(1) bond length. There is one shorter (3.18 Å) and one longer (3.28 Å) Ca(1)-I(2) bond length. Pb(1) is bonded in a rectangular see-saw-like geometry to one I(1), one I(2), one I(3), and one I(4) atom. The Pb(1)-I(1) bond length is 3.20 Å. The Pb(1)-I(2) bond length is 3.14 Å. The Pb(1)-I(3) bond length is 3.03 Å. The Pb(1)-I(4) bond length is 3.20 Å. There are four inequivalent I sites. In the first I site, I(1) is bonded in a distorted T-shaped geometry to two equivalent Ca(1) and one Pb(1) atom. In the second I site, I(2) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Pb(1) atom. In the third I site, I(3) is bonded in an L-shaped geometry to one Ca(1) and one Pb(1) atom. In the fourth I site, I(4) is bonded in a bent 120 degrees geometry to one Ca(1) and one Pb(1) atom.