Au3Cu is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Au sites. In the first Au site, Au(1) is bonded to four equivalent Au(1), four equivalent Au(2), and four equivalent Cu(1) atoms to form distorted AuCu4Au8 cuboctahedra that share corners with twelve equivalent Au(1)Cu4Au8 cuboctahedra, edges with eight equivalent Au(1)Cu4Au8 cuboctahedra, edges with eight equivalent Cu(1)Au12 cuboctahedra, faces with four equivalent Cu(1)Au12 cuboctahedra, and faces with ten equivalent Au(1)Cu4Au8 cuboctahedra. In the second Au site, Au(2) is bonded in a distorted square co-planar geometry to eight equivalent Au(1) and four equivalent Cu(1) atoms. Cu(1) is bonded to four equivalent Au(2) and eight equivalent Au(1) atoms to form CuAu12 cuboctahedra that share corners with four equivalent Cu(1)Au12 cuboctahedra, edges with eight equivalent Cu(1)Au12 cuboctahedra, edges with sixteen equivalent Au(1)Cu4Au8 cuboctahedra, faces with four equivalent Cu(1)Au12 cuboctahedra, and faces with eight equivalent Au(1)Cu4Au8 cuboctahedra.
Au3Cu is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Au sites. In the first Au site, Au(1) is bonded to four equivalent Au(1), four equivalent Au(2), and four equivalent Cu(1) atoms to form distorted AuCu4Au8 cuboctahedra that share corners with twelve equivalent Au(1)Cu4Au8 cuboctahedra, edges with eight equivalent Au(1)Cu4Au8 cuboctahedra, edges with eight equivalent Cu(1)Au12 cuboctahedra, faces with four equivalent Cu(1)Au12 cuboctahedra, and faces with ten equivalent Au(1)Cu4Au8 cuboctahedra. All Au(1)-Au(1) bond lengths are 2.82 Å. All Au(1)-Au(2) bond lengths are 2.85 Å. All Au(1)-Cu(1) bond lengths are 2.85 Å. In the second Au site, Au(2) is bonded in a distorted square co-planar geometry to eight equivalent Au(1) and four equivalent Cu(1) atoms. All Au(2)-Cu(1) bond lengths are 2.82 Å. Cu(1) is bonded to four equivalent Au(2) and eight equivalent Au(1) atoms to form CuAu12 cuboctahedra that share corners with four equivalent Cu(1)Au12 cuboctahedra, edges with eight equivalent Cu(1)Au12 cuboctahedra, edges with sixteen equivalent Au(1)Cu4Au8 cuboctahedra, faces with four equivalent Cu(1)Au12 cuboctahedra, and faces with eight equivalent Au(1)Cu4Au8 cuboctahedra.