Pm3Cu is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to four equivalent Pm(1), four equivalent Pm(2), and four equivalent Cu(1) atoms to form distorted PmPm8Cu4 cuboctahedra that share corners with twelve equivalent Pm(1)Pm8Cu4 cuboctahedra, edges with eight equivalent Pm(1)Pm8Cu4 cuboctahedra, edges with eight equivalent Cu(1)Pm12 cuboctahedra, faces with four equivalent Cu(1)Pm12 cuboctahedra, and faces with ten equivalent Pm(1)Pm8Cu4 cuboctahedra. In the second Pm site, Pm(2) is bonded in a distorted square co-planar geometry to eight equivalent Pm(1) and four equivalent Cu(1) atoms. Cu(1) is bonded to four equivalent Pm(2) and eight equivalent Pm(1) atoms to form CuPm12 cuboctahedra that share corners with four equivalent Cu(1)Pm12 cuboctahedra, edges with eight equivalent Cu(1)Pm12 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Cu4 cuboctahedra, faces with four equivalent Cu(1)Pm12 cuboctahedra, and faces with eight equivalent Pm(1)Pm8Cu4 cuboctahedra.
Pm3Cu is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to four equivalent Pm(1), four equivalent Pm(2), and four equivalent Cu(1) atoms to form distorted PmPm8Cu4 cuboctahedra that share corners with twelve equivalent Pm(1)Pm8Cu4 cuboctahedra, edges with eight equivalent Pm(1)Pm8Cu4 cuboctahedra, edges with eight equivalent Cu(1)Pm12 cuboctahedra, faces with four equivalent Cu(1)Pm12 cuboctahedra, and faces with ten equivalent Pm(1)Pm8Cu4 cuboctahedra. All Pm(1)-Pm(1) bond lengths are 3.31 Å. All Pm(1)-Pm(2) bond lengths are 3.44 Å. All Pm(1)-Cu(1) bond lengths are 3.44 Å. In the second Pm site, Pm(2) is bonded in a distorted square co-planar geometry to eight equivalent Pm(1) and four equivalent Cu(1) atoms. All Pm(2)-Cu(1) bond lengths are 3.31 Å. Cu(1) is bonded to four equivalent Pm(2) and eight equivalent Pm(1) atoms to form CuPm12 cuboctahedra that share corners with four equivalent Cu(1)Pm12 cuboctahedra, edges with eight equivalent Cu(1)Pm12 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Cu4 cuboctahedra, faces with four equivalent Cu(1)Pm12 cuboctahedra, and faces with eight equivalent Pm(1)Pm8Cu4 cuboctahedra.