CaPbI4 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to one I(1), one I(2), one I(3), and one I(4) atom to form CaI4 tetrahedra that share corners with two equivalent Pb(1)I6 octahedra and edges with two equivalent Pb(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 61-67°. Pb(1) is bonded to one I(3), one I(4), two equivalent I(1), and two equivalent I(2) atoms to form PbI6 octahedra that share corners with two equivalent Pb(1)I6 octahedra, corners with two equivalent Ca(1)I4 tetrahedra,  an edgeedge with one Pb(1)I6 octahedra, and edges with two equivalent Ca(1)I4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are four inequivalent I sites. In the first I site, I(1) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Pb(1) atoms. In the second I site, I(2) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Pb(1) atoms. 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(1), one I(2), one I(3), and one I(4) atom to form CaI4 tetrahedra that share corners with two equivalent Pb(1)I6 octahedra and edges with two equivalent Pb(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 61-67°. The Ca(1)-I(1) bond length is 3.02 Å. The Ca(1)-I(2) bond length is 3.05 Å. The Ca(1)-I(3) bond length is 2.99 Å. The Ca(1)-I(4) bond length is 3.00 Å. Pb(1) is bonded to one I(3), one I(4), two equivalent I(1), and two equivalent I(2) atoms to form PbI6 octahedra that share corners with two equivalent Pb(1)I6 octahedra, corners with two equivalent Ca(1)I4 tetrahedra,  an edgeedge with one Pb(1)I6 octahedra, and edges with two equivalent Ca(1)I4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. The Pb(1)-I(3) bond length is 3.13 Å. The Pb(1)-I(4) bond length is 3.15 Å. There is one shorter (3.31 Å) and one longer (3.42 Å) Pb(1)-I(1) bond length. There is one shorter (3.26 Å) and one longer (3.45 Å) Pb(1)-I(2) bond length. There are four inequivalent I sites. In the first I site, I(1) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Pb(1) atoms. In the second I site, I(2) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Pb(1) atoms. 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.