BaCuS2 crystallizes in the tetragonal I-4m2 space group. Ba(1) is bonded to four equivalent Cu(1) and eight equivalent S(1) atoms to form distorted BaCu4S8 cuboctahedra that share corners with eight equivalent Ba(1)Cu4S8 cuboctahedra, corners with eight equivalent Cu(1)Ba4S4 tetrahedra, edges with four equivalent Ba(1)Cu4S8 cuboctahedra, edges with four equivalent Cu(1)Ba4S4 tetrahedra, and faces with four equivalent Ba(1)Cu4S8 cuboctahedra. Cu(1) is bonded to four equivalent Ba(1) and four equivalent S(1) atoms to form distorted CuBa4S4 tetrahedra that share corners with eight equivalent Ba(1)Cu4S8 cuboctahedra, corners with eight equivalent Cu(1)Ba4S4 tetrahedra, edges with four equivalent Ba(1)Cu4S8 cuboctahedra, and edges with four equivalent Cu(1)Ba4S4 tetrahedra. S(1) is bonded in a distorted bent 120 degrees geometry to four equivalent Ba(1) and two equivalent Cu(1) atoms.
BaCuS2 crystallizes in the tetragonal I-4m2 space group. Ba(1) is bonded to four equivalent Cu(1) and eight equivalent S(1) atoms to form distorted BaCu4S8 cuboctahedra that share corners with eight equivalent Ba(1)Cu4S8 cuboctahedra, corners with eight equivalent Cu(1)Ba4S4 tetrahedra, edges with four equivalent Ba(1)Cu4S8 cuboctahedra, edges with four equivalent Cu(1)Ba4S4 tetrahedra, and faces with four equivalent Ba(1)Cu4S8 cuboctahedra. All Ba(1)-Cu(1) bond lengths are 3.43 Å. All Ba(1)-S(1) bond lengths are 3.28 Å. Cu(1) is bonded to four equivalent Ba(1) and four equivalent S(1) atoms to form distorted CuBa4S4 tetrahedra that share corners with eight equivalent Ba(1)Cu4S8 cuboctahedra, corners with eight equivalent Cu(1)Ba4S4 tetrahedra, edges with four equivalent Ba(1)Cu4S8 cuboctahedra, and edges with four equivalent Cu(1)Ba4S4 tetrahedra. All Cu(1)-S(1) bond lengths are 2.33 Å. S(1) is bonded in a distorted bent 120 degrees geometry to four equivalent Ba(1) and two equivalent Cu(1) atoms.