YbCuS2 is Ilmenite-like structured and crystallizes in the orthorhombic P2_12_12_1 space group. Yb(1) is bonded to three equivalent S(1) and three equivalent S(2) atoms to form distorted YbS6 octahedra that share corners with four equivalent Yb(1)S6 octahedra, corners with six equivalent Cu(1)S4 tetrahedra, edges with four equivalent Yb(1)S6 octahedra, and edges with three equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-55°. Cu(1) is bonded to one S(2) and three equivalent S(1) atoms to form CuS4 tetrahedra that share corners with six equivalent Yb(1)S6 octahedra, corners with two equivalent Cu(1)S4 tetrahedra, edges with three equivalent Yb(1)S6 octahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 17-64°. There are two inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Yb(1) and three equivalent Cu(1) atoms to form distorted edge-sharing SYb3Cu3 octahedra. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to three equivalent Yb(1) and one Cu(1) atom.
YbCuS2 is Ilmenite-like structured and crystallizes in the orthorhombic P2_12_12_1 space group. Yb(1) is bonded to three equivalent S(1) and three equivalent S(2) atoms to form distorted YbS6 octahedra that share corners with four equivalent Yb(1)S6 octahedra, corners with six equivalent Cu(1)S4 tetrahedra, edges with four equivalent Yb(1)S6 octahedra, and edges with three equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-55°. There are two shorter (2.89 Å) and one longer (2.93 Å) Yb(1)-S(1) bond length. There are a spread of Yb(1)-S(2) bond distances ranging from 2.69-2.74 Å. Cu(1) is bonded to one S(2) and three equivalent S(1) atoms to form CuS4 tetrahedra that share corners with six equivalent Yb(1)S6 octahedra, corners with two equivalent Cu(1)S4 tetrahedra, edges with three equivalent Yb(1)S6 octahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 17-64°. The Cu(1)-S(2) bond length is 2.22 Å. There are a spread of Cu(1)-S(1) bond distances ranging from 2.32-2.36 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Yb(1) and three equivalent Cu(1) atoms to form distorted edge-sharing SYb3Cu3 octahedra. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to three equivalent Yb(1) and one Cu(1) atom.