CuGeI3 crystallizes in the tetragonal I4/mcm space group. Cu(1) is bonded in a 4-coordinate geometry to four equivalent I(2) atoms. Ge(1) is bonded to two equivalent I(1) and four equivalent I(2) atoms to form corner-sharing GeI6 octahedra. The corner-sharing octahedral tilt angles range from 0-40°. There are two inequivalent I sites. In the first I site, I(1) is bonded in a linear geometry to two equivalent Ge(1) atoms. In the second I site, I(2) is bonded to two equivalent Cu(1) and two equivalent Ge(1) atoms to form a mixture of edge and corner-sharing ICu2Ge2 tetrahedra.
CuGeI3 crystallizes in the tetragonal I4/mcm space group. Cu(1) is bonded in a 4-coordinate geometry to four equivalent I(2) atoms. All Cu(1)-I(2) bond lengths are 3.30 Å. Ge(1) is bonded to two equivalent I(1) and four equivalent I(2) atoms to form corner-sharing GeI6 octahedra. The corner-sharing octahedral tilt angles range from 0-40°. Both Ge(1)-I(1) bond lengths are 2.75 Å. All Ge(1)-I(2) bond lengths are 3.05 Å. There are two inequivalent I sites. In the first I site, I(1) is bonded in a linear geometry to two equivalent Ge(1) atoms. In the second I site, I(2) is bonded to two equivalent Cu(1) and two equivalent Ge(1) atoms to form a mixture of edge and corner-sharing ICu2Ge2 tetrahedra.