La2CuInSe5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to one Se(5), two equivalent Se(1), two equivalent Se(3), and three equivalent Se(2) atoms. In the second La site, La(2) is bonded in a 9-coordinate geometry to one Cu(1), two equivalent Se(1), two equivalent Se(3), two equivalent Se(4), and two equivalent Se(5) atoms. Cu(1) is bonded to one La(2), one Se(3), and three equivalent Se(4) atoms to form distorted CuLaSe4 tetrahedra that share corners with three equivalent In(1)Se6 octahedra, corners with two equivalent Se(1)La4In square pyramids, corners with two equivalent Cu(1)LaSe4 tetrahedra, corners with two equivalent Se(5)La3In2 trigonal bipyramids, corners with two equivalent Se(3)La4Cu trigonal bipyramids, and edges with two equivalent Cu(1)LaSe4 tetrahedra. The corner-sharing octahedral tilt angles range from 9-71°. In(1) is bonded to one Se(1), one Se(4), two equivalent Se(2), and two equivalent Se(5) atoms to form InSe6 octahedra that share corners with three equivalent Cu(1)LaSe4 tetrahedra and edges with two equivalent In(1)Se6 octahedra. There are five inequivalent Se sites. In the first Se site, Se(5) is bonded to one La(1), two equivalent La(2), and two equivalent In(1) atoms to form distorted SeLa3In2 trigonal bipyramids that share corners with two equivalent Cu(1)LaSe4 tetrahedra, corners with two equivalent Se(3)La4Cu trigonal bipyramids, corners with four equivalent Se(5)La3In2 trigonal bipyramids, corners with five equivalent Se(2)La3In2 trigonal bipyramids, edges with four equivalent Se(1)La4In square pyramids,  an edgeedge with one Se(2)La3In2 trigonal bipyramid, and edges with two equivalent Se(3)La4Cu trigonal bipyramids. In the second Se site, Se(1) is bonded to two equivalent La(1), two equivalent La(2), and one In(1) atom to form SeLa4In square pyramids that share corners with two equivalent Cu(1)LaSe4 tetrahedra, corners with two equivalent Se(2)La3In2 trigonal bipyramids, corners with four equivalent Se(3)La4Cu trigonal bipyramids, edges with two equivalent Se(1)La4In square pyramids, edges with two equivalent Se(3)La4Cu trigonal bipyramids, edges with three equivalent Se(2)La3In2 trigonal bipyramids, and edges with four equivalent Se(5)La3In2 trigonal bipyramids. In the third Se site, Se(2) is bonded to three equivalent La(1) and two equivalent In(1) atoms to form SeLa3In2 trigonal bipyramids that share corners with two equivalent Se(1)La4In square pyramids, corners with four equivalent Se(3)La4Cu trigonal bipyramids, corners with five equivalent Se(5)La3In2 trigonal bipyramids, edges with three equivalent Se(1)La4In square pyramids,  an edgeedge with one Se(5)La3In2 trigonal bipyramid,  an edgeedge with one Se(3)La4Cu trigonal bipyramid, and edges with four equivalent Se(2)La3In2 trigonal bipyramids. In the fourth Se site, Se(3) is bonded to two equivalent La(1), two equivalent La(2), and one Cu(1) atom to form distorted SeLa4Cu trigonal bipyramids that share corners with four equivalent Se(1)La4In square pyramids, corners with two equivalent Cu(1)LaSe4 tetrahedra, corners with two equivalent Se(5)La3In2 trigonal bipyramids, corners with four equivalent Se(2)La3In2 trigonal bipyramids, edges with two equivalent Se(1)La4In square pyramids,  an edgeedge with one Se(2)La3In2 trigonal bipyramid, edges with two equivalent Se(5)La3In2 trigonal bipyramids, and edges with two equivalent Se(3)La4Cu trigonal bipyramids. In the fifth Se site, Se(4) is bonded in a 6-coordinate geometry to two equivalent La(2), three equivalent Cu(1), and one In(1) atom.
La2CuInSe5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to one Se(5), two equivalent Se(1), two equivalent Se(3), and three equivalent Se(2) atoms. The La(1)-Se(5) bond length is 3.37 Å. Both La(1)-Se(1) bond lengths are 3.11 Å. Both La(1)-Se(3) bond lengths are 3.05 Å. There are two shorter (3.11 Å) and one longer (3.16 Å) La(1)-Se(2) bond length. In the second La site, La(2) is bonded in a 9-coordinate geometry to one Cu(1), two equivalent Se(1), two equivalent Se(3), two equivalent Se(4), and two equivalent Se(5) atoms. The La(2)-Cu(1) bond length is 3.32 Å. Both La(2)-Se(1) bond lengths are 3.08 Å. Both La(2)-Se(3) bond lengths are 3.07 Å. Both La(2)-Se(4) bond lengths are 3.12 Å. There is one shorter (3.33 Å) and one longer (3.34 Å) La(2)-Se(5) bond length. Cu(1) is bonded to one La(2), one Se(3), and three equivalent Se(4) atoms to form distorted CuLaSe4 tetrahedra that share corners with three equivalent In(1)Se6 octahedra, corners with two equivalent Se(1)La4In square pyramids, corners with two equivalent Cu(1)LaSe4 tetrahedra, corners with two equivalent Se(5)La3In2 trigonal bipyramids, corners with two equivalent Se(3)La4Cu trigonal bipyramids, and edges with two equivalent Cu(1)LaSe4 tetrahedra. The corner-sharing octahedral tilt angles range from 9-71°. The Cu(1)-Se(3) bond length is 2.42 Å. There are two shorter (2.47 Å) and one longer (2.58 Å) Cu(1)-Se(4) bond length. In(1) is bonded to one Se(1), one Se(4), two equivalent Se(2), and two equivalent Se(5) atoms to form InSe6 octahedra that share corners with three equivalent Cu(1)LaSe4 tetrahedra and edges with two equivalent In(1)Se6 octahedra. The In(1)-Se(1) bond length is 2.72 Å. The In(1)-Se(4) bond length is 2.77 Å. Both In(1)-Se(2) bond lengths are 2.93 Å. Both In(1)-Se(5) bond lengths are 2.74 Å. There are five inequivalent Se sites. In the first Se site, Se(5) is bonded to one La(1), two equivalent La(2), and two equivalent In(1) atoms to form distorted SeLa3In2 trigonal bipyramids that share corners with two equivalent Cu(1)LaSe4 tetrahedra, corners with two equivalent Se(3)La4Cu trigonal bipyramids, corners with four equivalent Se(5)La3In2 trigonal bipyramids, corners with five equivalent Se(2)La3In2 trigonal bipyramids, edges with four equivalent Se(1)La4In square pyramids,  an edgeedge with one Se(2)La3In2 trigonal bipyramid, and edges with two equivalent Se(3)La4Cu trigonal bipyramids. In the second Se site, Se(1) is bonded to two equivalent La(1), two equivalent La(2), and one In(1) atom to form SeLa4In square pyramids that share corners with two equivalent Cu(1)LaSe4 tetrahedra, corners with two equivalent Se(2)La3In2 trigonal bipyramids, corners with four equivalent Se(3)La4Cu trigonal bipyramids, edges with two equivalent Se(1)La4In square pyramids, edges with two equivalent Se(3)La4Cu trigonal bipyramids, edges with three equivalent Se(2)La3In2 trigonal bipyramids, and edges with four equivalent Se(5)La3In2 trigonal bipyramids. In the third Se site, Se(2) is bonded to three equivalent La(1) and two equivalent In(1) atoms to form SeLa3In2 trigonal bipyramids that share corners with two equivalent Se(1)La4In square pyramids, corners with four equivalent Se(3)La4Cu trigonal bipyramids, corners with five equivalent Se(5)La3In2 trigonal bipyramids, edges with three equivalent Se(1)La4In square pyramids,  an edgeedge with one Se(5)La3In2 trigonal bipyramid,  an edgeedge with one Se(3)La4Cu trigonal bipyramid, and edges with four equivalent Se(2)La3In2 trigonal bipyramids. In the fourth Se site, Se(3) is bonded to two equivalent La(1), two equivalent La(2), and one Cu(1) atom to form distorted SeLa4Cu trigonal bipyramids that share corners with four equivalent Se(1)La4In square pyramids, corners with two equivalent Cu(1)LaSe4 tetrahedra, corners with two equivalent Se(5)La3In2 trigonal bipyramids, corners with four equivalent Se(2)La3In2 trigonal bipyramids, edges with two equivalent Se(1)La4In square pyramids,  an edgeedge with one Se(2)La3In2 trigonal bipyramid, edges with two equivalent Se(5)La3In2 trigonal bipyramids, and edges with two equivalent Se(3)La4Cu trigonal bipyramids. In the fifth Se site, Se(4) is bonded in a 6-coordinate geometry to two equivalent La(2), three equivalent Cu(1), and one In(1) atom.