Ce2CuInSe5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 8-coordinate geometry to one Se(2), two equivalent Se(3), two equivalent Se(4), and three equivalent Se(1) atoms. In the second Ce site, Ce(2) is bonded in a 9-coordinate geometry to one Cu(1), two equivalent Se(2), two equivalent Se(3), two equivalent Se(4), and two equivalent Se(5) atoms. Cu(1) is bonded in a 4-coordinate geometry to one Ce(2), one Se(4), and three equivalent Se(5) atoms. In(1) is bonded to one Se(3), one Se(5), two equivalent Se(1), and two equivalent Se(2) atoms to form edge-sharing InSe6 octahedra. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Ce(1) and two equivalent In(1) atoms to form SeCe3In2 trigonal bipyramids that share corners with two equivalent Se(3)Ce4In square pyramids, corners with four equivalent Se(4)Ce4Cu trigonal bipyramids, corners with five equivalent Se(2)Ce3In2 trigonal bipyramids, edges with three equivalent Se(3)Ce4In square pyramids,  an edgeedge with one Se(2)Ce3In2 trigonal bipyramid,  an edgeedge with one Se(4)Ce4Cu trigonal bipyramid, and edges with four equivalent Se(1)Ce3In2 trigonal bipyramids. In the second Se site, Se(2) is bonded to one Ce(1), two equivalent Ce(2), and two equivalent In(1) atoms to form SeCe3In2 trigonal bipyramids that share corners with two equivalent Se(4)Ce4Cu trigonal bipyramids, corners with four equivalent Se(2)Ce3In2 trigonal bipyramids, corners with five equivalent Se(1)Ce3In2 trigonal bipyramids, edges with four equivalent Se(3)Ce4In square pyramids,  an edgeedge with one Se(1)Ce3In2 trigonal bipyramid, and edges with two equivalent Se(4)Ce4Cu trigonal bipyramids. In the third Se site, Se(3) is bonded to two equivalent Ce(1), two equivalent Ce(2), and one In(1) atom to form SeCe4In square pyramids that share corners with two equivalent Se(1)Ce3In2 trigonal bipyramids, corners with four equivalent Se(4)Ce4Cu trigonal bipyramids, edges with two equivalent Se(3)Ce4In square pyramids, edges with two equivalent Se(4)Ce4Cu trigonal bipyramids, edges with three equivalent Se(1)Ce3In2 trigonal bipyramids, and edges with four equivalent Se(2)Ce3In2 trigonal bipyramids. In the fourth Se site, Se(4) is bonded to two equivalent Ce(1), two equivalent Ce(2), and one Cu(1) atom to form SeCe4Cu trigonal bipyramids that share corners with four equivalent Se(3)Ce4In square pyramids, corners with two equivalent Se(2)Ce3In2 trigonal bipyramids, corners with four equivalent Se(1)Ce3In2 trigonal bipyramids, edges with two equivalent Se(3)Ce4In square pyramids,  an edgeedge with one Se(1)Ce3In2 trigonal bipyramid, edges with two equivalent Se(2)Ce3In2 trigonal bipyramids, and edges with two equivalent Se(4)Ce4Cu trigonal bipyramids. In the fifth Se site, Se(5) is bonded in a 6-coordinate geometry to two equivalent Ce(2), three equivalent Cu(1), and one In(1) atom.
Ce2CuInSe5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 8-coordinate geometry to one Se(2), two equivalent Se(3), two equivalent Se(4), and three equivalent Se(1) atoms. The Ce(1)-Se(2) bond length is 3.25 Å. Both Ce(1)-Se(3) bond lengths are 3.06 Å. Both Ce(1)-Se(4) bond lengths are 3.01 Å. There are two shorter (3.07 Å) and one longer (3.12 Å) Ce(1)-Se(1) bond length. In the second Ce site, Ce(2) is bonded in a 9-coordinate geometry to one Cu(1), two equivalent Se(2), two equivalent Se(3), two equivalent Se(4), and two equivalent Se(5) atoms. The Ce(2)-Cu(1) bond length is 3.28 Å. There is one shorter (3.28 Å) and one longer (3.29 Å) Ce(2)-Se(2) bond length. Both Ce(2)-Se(3) bond lengths are 3.03 Å. Both Ce(2)-Se(4) bond lengths are 3.03 Å. Both Ce(2)-Se(5) bond lengths are 3.07 Å. Cu(1) is bonded in a 4-coordinate geometry to one Ce(2), one Se(4), and three equivalent Se(5) atoms. The Cu(1)-Se(4) bond length is 2.41 Å. There are two shorter (2.43 Å) and one longer (2.61 Å) Cu(1)-Se(5) bond length. In(1) is bonded to one Se(3), one Se(5), two equivalent Se(1), and two equivalent Se(2) atoms to form edge-sharing InSe6 octahedra. The In(1)-Se(3) bond length is 2.71 Å. The In(1)-Se(5) bond length is 2.75 Å. Both In(1)-Se(1) bond lengths are 2.91 Å. Both In(1)-Se(2) bond lengths are 2.75 Å. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Ce(1) and two equivalent In(1) atoms to form SeCe3In2 trigonal bipyramids that share corners with two equivalent Se(3)Ce4In square pyramids, corners with four equivalent Se(4)Ce4Cu trigonal bipyramids, corners with five equivalent Se(2)Ce3In2 trigonal bipyramids, edges with three equivalent Se(3)Ce4In square pyramids,  an edgeedge with one Se(2)Ce3In2 trigonal bipyramid,  an edgeedge with one Se(4)Ce4Cu trigonal bipyramid, and edges with four equivalent Se(1)Ce3In2 trigonal bipyramids. In the second Se site, Se(2) is bonded to one Ce(1), two equivalent Ce(2), and two equivalent In(1) atoms to form SeCe3In2 trigonal bipyramids that share corners with two equivalent Se(4)Ce4Cu trigonal bipyramids, corners with four equivalent Se(2)Ce3In2 trigonal bipyramids, corners with five equivalent Se(1)Ce3In2 trigonal bipyramids, edges with four equivalent Se(3)Ce4In square pyramids,  an edgeedge with one Se(1)Ce3In2 trigonal bipyramid, and edges with two equivalent Se(4)Ce4Cu trigonal bipyramids. In the third Se site, Se(3) is bonded to two equivalent Ce(1), two equivalent Ce(2), and one In(1) atom to form SeCe4In square pyramids that share corners with two equivalent Se(1)Ce3In2 trigonal bipyramids, corners with four equivalent Se(4)Ce4Cu trigonal bipyramids, edges with two equivalent Se(3)Ce4In square pyramids, edges with two equivalent Se(4)Ce4Cu trigonal bipyramids, edges with three equivalent Se(1)Ce3In2 trigonal bipyramids, and edges with four equivalent Se(2)Ce3In2 trigonal bipyramids. In the fourth Se site, Se(4) is bonded to two equivalent Ce(1), two equivalent Ce(2), and one Cu(1) atom to form SeCe4Cu trigonal bipyramids that share corners with four equivalent Se(3)Ce4In square pyramids, corners with two equivalent Se(2)Ce3In2 trigonal bipyramids, corners with four equivalent Se(1)Ce3In2 trigonal bipyramids, edges with two equivalent Se(3)Ce4In square pyramids,  an edgeedge with one Se(1)Ce3In2 trigonal bipyramid, edges with two equivalent Se(2)Ce3In2 trigonal bipyramids, and edges with two equivalent Se(4)Ce4Cu trigonal bipyramids. In the fifth Se site, Se(5) is bonded in a 6-coordinate geometry to two equivalent Ce(2), three equivalent Cu(1), and one In(1) atom.