Pm3Hf is beta Cu3Ti-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 Hf(1) atoms to form PmPm8Hf4 cuboctahedra that share corners with twelve equivalent Pm(1)Pm8Hf4 cuboctahedra, edges with eight equivalent Pm(1)Pm8Hf4 cuboctahedra, edges with eight equivalent Pm(2)Pm8Hf4 cuboctahedra, edges with eight equivalent Hf(1)Pm12 cuboctahedra, faces with four equivalent Pm(2)Pm8Hf4 cuboctahedra, faces with four equivalent Hf(1)Pm12 cuboctahedra, and faces with ten equivalent Pm(1)Pm8Hf4 cuboctahedra. In the second Pm site, Pm(2) is bonded to eight equivalent Pm(1) and four equivalent Hf(1) atoms to form PmPm8Hf4 cuboctahedra that share corners with four equivalent Pm(2)Pm8Hf4 cuboctahedra, corners with eight equivalent Hf(1)Pm12 cuboctahedra, edges with eight equivalent Pm(2)Pm8Hf4 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Hf4 cuboctahedra, faces with four equivalent Pm(2)Pm8Hf4 cuboctahedra, faces with six equivalent Hf(1)Pm12 cuboctahedra, and faces with eight equivalent Pm(1)Pm8Hf4 cuboctahedra. Hf(1) is bonded to four equivalent Pm(2) and eight equivalent Pm(1) atoms to form HfPm12 cuboctahedra that share corners with four equivalent Hf(1)Pm12 cuboctahedra, corners with eight equivalent Pm(2)Pm8Hf4 cuboctahedra, edges with eight equivalent Hf(1)Pm12 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Hf4 cuboctahedra, faces with four equivalent Hf(1)Pm12 cuboctahedra, faces with six equivalent Pm(2)Pm8Hf4 cuboctahedra, and faces with eight equivalent Pm(1)Pm8Hf4 cuboctahedra.
Pm3Hf is beta Cu3Ti-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 Hf(1) atoms to form PmPm8Hf4 cuboctahedra that share corners with twelve equivalent Pm(1)Pm8Hf4 cuboctahedra, edges with eight equivalent Pm(1)Pm8Hf4 cuboctahedra, edges with eight equivalent Pm(2)Pm8Hf4 cuboctahedra, edges with eight equivalent Hf(1)Pm12 cuboctahedra, faces with four equivalent Pm(2)Pm8Hf4 cuboctahedra, faces with four equivalent Hf(1)Pm12 cuboctahedra, and faces with ten equivalent Pm(1)Pm8Hf4 cuboctahedra. All Pm(1)-Pm(1) bond lengths are 3.51 Å. All Pm(1)-Pm(2) bond lengths are 3.51 Å. All Pm(1)-Hf(1) bond lengths are 3.51 Å. In the second Pm site, Pm(2) is bonded to eight equivalent Pm(1) and four equivalent Hf(1) atoms to form PmPm8Hf4 cuboctahedra that share corners with four equivalent Pm(2)Pm8Hf4 cuboctahedra, corners with eight equivalent Hf(1)Pm12 cuboctahedra, edges with eight equivalent Pm(2)Pm8Hf4 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Hf4 cuboctahedra, faces with four equivalent Pm(2)Pm8Hf4 cuboctahedra, faces with six equivalent Hf(1)Pm12 cuboctahedra, and faces with eight equivalent Pm(1)Pm8Hf4 cuboctahedra. All Pm(2)-Hf(1) bond lengths are 3.51 Å. Hf(1) is bonded to four equivalent Pm(2) and eight equivalent Pm(1) atoms to form HfPm12 cuboctahedra that share corners with four equivalent Hf(1)Pm12 cuboctahedra, corners with eight equivalent Pm(2)Pm8Hf4 cuboctahedra, edges with eight equivalent Hf(1)Pm12 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Hf4 cuboctahedra, faces with four equivalent Hf(1)Pm12 cuboctahedra, faces with six equivalent Pm(2)Pm8Hf4 cuboctahedra, and faces with eight equivalent Pm(1)Pm8Hf4 cuboctahedra.