KGd2CuS4 crystallizes in the orthorhombic Cmcm space group. K(1) is bonded in a 6-coordinate geometry to two equivalent S(3) and four equivalent S(1) atoms. Gd(1) is bonded to one S(3), two equivalent S(2), and three equivalent S(1) atoms to form GdS6 octahedra that share corners with three equivalent Gd(1)S6 octahedra,  a cornercorner with one Cu(1)S4 tetrahedra, edges with five equivalent Gd(1)S6 octahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 0-37°. Cu(1) is bonded to two equivalent S(1) and two equivalent S(3) atoms to form CuS4 tetrahedra that share corners with two equivalent Gd(1)S6 octahedra, corners with two equivalent Cu(1)S4 tetrahedra, and edges with four equivalent Gd(1)S6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are three inequivalent S sites. In the first S site, S(1) is bonded to two equivalent K(1), three equivalent Gd(1), and one Cu(1) atom to form a mixture of distorted edge, corner, and face-sharing SK2Gd3Cu octahedra. The corner-sharing octahedral tilt angles are 65°. In the second S site, S(2) is bonded in a square co-planar geometry to four equivalent Gd(1) atoms. In the third S site, S(3) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent Gd(1), and two equivalent Cu(1) atoms.
KGd2CuS4 crystallizes in the orthorhombic Cmcm space group. K(1) is bonded in a 6-coordinate geometry to two equivalent S(3) and four equivalent S(1) atoms. Both K(1)-S(3) bond lengths are 3.16 Å. All K(1)-S(1) bond lengths are 3.28 Å. Gd(1) is bonded to one S(3), two equivalent S(2), and three equivalent S(1) atoms to form GdS6 octahedra that share corners with three equivalent Gd(1)S6 octahedra,  a cornercorner with one Cu(1)S4 tetrahedra, edges with five equivalent Gd(1)S6 octahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 0-37°. The Gd(1)-S(3) bond length is 2.74 Å. Both Gd(1)-S(2) bond lengths are 2.85 Å. There are two shorter (2.74 Å) and one longer (2.79 Å) Gd(1)-S(1) bond length. Cu(1) is bonded to two equivalent S(1) and two equivalent S(3) atoms to form CuS4 tetrahedra that share corners with two equivalent Gd(1)S6 octahedra, corners with two equivalent Cu(1)S4 tetrahedra, and edges with four equivalent Gd(1)S6 octahedra. The corner-sharing octahedral tilt angles are 5°. Both Cu(1)-S(1) bond lengths are 2.34 Å. Both Cu(1)-S(3) bond lengths are 2.37 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded to two equivalent K(1), three equivalent Gd(1), and one Cu(1) atom to form a mixture of distorted edge, corner, and face-sharing SK2Gd3Cu octahedra. The corner-sharing octahedral tilt angles are 65°. In the second S site, S(2) is bonded in a square co-planar geometry to four equivalent Gd(1) atoms. In the third S site, S(3) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent Gd(1), and two equivalent Cu(1) atoms.