Cd3AsI3 crystallizes in the monoclinic Pm space group. There are three inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one As(1), one I(3), and two equivalent I(2) atoms to form CdAsI3 tetrahedra that share corners with two equivalent Cd(1)AsI3 tetrahedra, corners with two equivalent Cd(3)AsI3 tetrahedra, and corners with four equivalent Cd(2)As2I2 tetrahedra. In the second Cd site, Cd(2) is bonded to two equivalent As(1), one I(1), and one I(2) atom to form CdAs2I2 tetrahedra that share corners with two equivalent Cd(2)As2I2 tetrahedra, corners with four equivalent Cd(1)AsI3 tetrahedra, and corners with four equivalent Cd(3)AsI3 tetrahedra. In the third Cd site, Cd(3) is bonded to one As(1), one I(3), and two equivalent I(1) atoms to form CdAsI3 tetrahedra that share corners with two equivalent Cd(1)AsI3 tetrahedra, corners with two equivalent Cd(3)AsI3 tetrahedra, and corners with four equivalent Cd(2)As2I2 tetrahedra. As(1) is bonded to one Cd(1), one Cd(3), and two equivalent Cd(2) atoms to form corner-sharing AsCd4 tetrahedra. There are three inequivalent I sites. In the first I site, I(1) is bonded in a trigonal non-coplanar geometry to one Cd(2) and two equivalent Cd(3) atoms. In the second I site, I(2) is bonded in a trigonal non-coplanar geometry to one Cd(2) and two equivalent Cd(1) atoms. In the third I site, I(3) is bonded in a water-like geometry to one Cd(1) and one Cd(3) atom.
Cd3AsI3 crystallizes in the monoclinic Pm space group. There are three inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one As(1), one I(3), and two equivalent I(2) atoms to form CdAsI3 tetrahedra that share corners with two equivalent Cd(1)AsI3 tetrahedra, corners with two equivalent Cd(3)AsI3 tetrahedra, and corners with four equivalent Cd(2)As2I2 tetrahedra. The Cd(1)-As(1) bond length is 2.57 Å. The Cd(1)-I(3) bond length is 2.83 Å. Both Cd(1)-I(2) bond lengths are 2.97 Å. In the second Cd site, Cd(2) is bonded to two equivalent As(1), one I(1), and one I(2) atom to form CdAs2I2 tetrahedra that share corners with two equivalent Cd(2)As2I2 tetrahedra, corners with four equivalent Cd(1)AsI3 tetrahedra, and corners with four equivalent Cd(3)AsI3 tetrahedra. Both Cd(2)-As(1) bond lengths are 2.57 Å. The Cd(2)-I(1) bond length is 3.01 Å. The Cd(2)-I(2) bond length is 3.01 Å. In the third Cd site, Cd(3) is bonded to one As(1), one I(3), and two equivalent I(1) atoms to form CdAsI3 tetrahedra that share corners with two equivalent Cd(1)AsI3 tetrahedra, corners with two equivalent Cd(3)AsI3 tetrahedra, and corners with four equivalent Cd(2)As2I2 tetrahedra. The Cd(3)-As(1) bond length is 2.56 Å. The Cd(3)-I(3) bond length is 2.83 Å. Both Cd(3)-I(1) bond lengths are 2.96 Å. As(1) is bonded to one Cd(1), one Cd(3), and two equivalent Cd(2) atoms to form corner-sharing AsCd4 tetrahedra. There are three inequivalent I sites. In the first I site, I(1) is bonded in a trigonal non-coplanar geometry to one Cd(2) and two equivalent Cd(3) atoms. In the second I site, I(2) is bonded in a trigonal non-coplanar geometry to one Cd(2) and two equivalent Cd(1) atoms. In the third I site, I(3) is bonded in a water-like geometry to one Cd(1) and one Cd(3) atom.