GdCuSe2 crystallizes in the monoclinic P2_1/c space group. Gd(1) is bonded in a 7-coordinate geometry to three equivalent Se(1) and four equivalent Se(2) atoms. Cu(1) is bonded to one Se(2) and three equivalent Se(1) atoms to form a mixture of distorted corner and edge-sharing CuSe4 tetrahedra. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to three equivalent Gd(1) and three equivalent Cu(1) atoms. In the second Se site, Se(2) is bonded to four equivalent Gd(1) and one Cu(1) atom to form a mixture of distorted corner and edge-sharing SeGd4Cu trigonal bipyramids.
GdCuSe2 crystallizes in the monoclinic P2_1/c space group. Gd(1) is bonded in a 7-coordinate geometry to three equivalent Se(1) and four equivalent Se(2) atoms. There are a spread of Gd(1)-Se(1) bond distances ranging from 2.94-3.18 Å. There are a spread of Gd(1)-Se(2) bond distances ranging from 2.89-2.96 Å. Cu(1) is bonded to one Se(2) and three equivalent Se(1) atoms to form a mixture of distorted corner and edge-sharing CuSe4 tetrahedra. The Cu(1)-Se(2) bond length is 2.44 Å. There are a spread of Cu(1)-Se(1) bond distances ranging from 2.43-2.59 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to three equivalent Gd(1) and three equivalent Cu(1) atoms. In the second Se site, Se(2) is bonded to four equivalent Gd(1) and one Cu(1) atom to form a mixture of distorted corner and edge-sharing SeGd4Cu trigonal bipyramids.