BaYCuS3 crystallizes in the orthorhombic Cmcm space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent S(2) and six equivalent S(1) atoms. Y(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form YS6 octahedra that share corners with two equivalent Y(1)S6 octahedra, edges with two equivalent Y(1)S6 octahedra, and edges with four equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. Cu(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(1)S4 tetrahedra and edges with four equivalent Y(1)S6 octahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to three equivalent Ba(1), two equivalent Y(1), and one Cu(1) atom. In the second S site, S(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Y(1), and two equivalent Cu(1) atoms.
BaYCuS3 crystallizes in the orthorhombic Cmcm space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent S(2) and six equivalent S(1) atoms. Both Ba(1)-S(2) bond lengths are 3.16 Å. There are four shorter (3.25 Å) and two longer (3.58 Å) Ba(1)-S(1) bond lengths. Y(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form YS6 octahedra that share corners with two equivalent Y(1)S6 octahedra, edges with two equivalent Y(1)S6 octahedra, and edges with four equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. Both Y(1)-S(2) bond lengths are 2.73 Å. All Y(1)-S(1) bond lengths are 2.78 Å. Cu(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(1)S4 tetrahedra and edges with four equivalent Y(1)S6 octahedra. Both Cu(1)-S(1) bond lengths are 2.34 Å. Both Cu(1)-S(2) bond lengths are 2.42 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to three equivalent Ba(1), two equivalent Y(1), and one Cu(1) atom. In the second S site, S(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Y(1), and two equivalent Cu(1) atoms.