HoPm3 crystallizes in the tetragonal I4/mmm space group. Ho(1) is bonded to four equivalent Pm(2) and eight equivalent Pm(1) atoms to form HoPm12 cuboctahedra that share corners with four equivalent Ho(1)Pm12 cuboctahedra, corners with eight equivalent Pm(2)Pm8Ho4 cuboctahedra, edges with eight equivalent Ho(1)Pm12 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Ho4 cuboctahedra, faces with four equivalent Ho(1)Pm12 cuboctahedra, faces with six equivalent Pm(2)Pm8Ho4 cuboctahedra, and faces with eight equivalent Pm(1)Pm8Ho4 cuboctahedra. There are two inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to four equivalent Ho(1), four equivalent Pm(1), and four equivalent Pm(2) atoms to form PmPm8Ho4 cuboctahedra that share corners with twelve equivalent Pm(1)Pm8Ho4 cuboctahedra, edges with eight equivalent Ho(1)Pm12 cuboctahedra, edges with eight equivalent Pm(1)Pm8Ho4 cuboctahedra, edges with eight equivalent Pm(2)Pm8Ho4 cuboctahedra, faces with four equivalent Ho(1)Pm12 cuboctahedra, faces with four equivalent Pm(2)Pm8Ho4 cuboctahedra, and faces with ten equivalent Pm(1)Pm8Ho4 cuboctahedra. In the second Pm site, Pm(2) is bonded to four equivalent Ho(1) and eight equivalent Pm(1) atoms to form PmPm8Ho4 cuboctahedra that share corners with four equivalent Pm(2)Pm8Ho4 cuboctahedra, corners with eight equivalent Ho(1)Pm12 cuboctahedra, edges with eight equivalent Pm(2)Pm8Ho4 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Ho4 cuboctahedra, faces with four equivalent Pm(2)Pm8Ho4 cuboctahedra, faces with six equivalent Ho(1)Pm12 cuboctahedra, and faces with eight equivalent Pm(1)Pm8Ho4 cuboctahedra.
HoPm3 crystallizes in the tetragonal I4/mmm space group. Ho(1) is bonded to four equivalent Pm(2) and eight equivalent Pm(1) atoms to form HoPm12 cuboctahedra that share corners with four equivalent Ho(1)Pm12 cuboctahedra, corners with eight equivalent Pm(2)Pm8Ho4 cuboctahedra, edges with eight equivalent Ho(1)Pm12 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Ho4 cuboctahedra, faces with four equivalent Ho(1)Pm12 cuboctahedra, faces with six equivalent Pm(2)Pm8Ho4 cuboctahedra, and faces with eight equivalent Pm(1)Pm8Ho4 cuboctahedra. All Ho(1)-Pm(2) bond lengths are 3.62 Å. All Ho(1)-Pm(1) bond lengths are 3.62 Å. There are two inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to four equivalent Ho(1), four equivalent Pm(1), and four equivalent Pm(2) atoms to form PmPm8Ho4 cuboctahedra that share corners with twelve equivalent Pm(1)Pm8Ho4 cuboctahedra, edges with eight equivalent Ho(1)Pm12 cuboctahedra, edges with eight equivalent Pm(1)Pm8Ho4 cuboctahedra, edges with eight equivalent Pm(2)Pm8Ho4 cuboctahedra, faces with four equivalent Ho(1)Pm12 cuboctahedra, faces with four equivalent Pm(2)Pm8Ho4 cuboctahedra, and faces with ten equivalent Pm(1)Pm8Ho4 cuboctahedra. All Pm(1)-Pm(1) bond lengths are 3.62 Å. All Pm(1)-Pm(2) bond lengths are 3.62 Å. In the second Pm site, Pm(2) is bonded to four equivalent Ho(1) and eight equivalent Pm(1) atoms to form PmPm8Ho4 cuboctahedra that share corners with four equivalent Pm(2)Pm8Ho4 cuboctahedra, corners with eight equivalent Ho(1)Pm12 cuboctahedra, edges with eight equivalent Pm(2)Pm8Ho4 cuboctahedra, edges with sixteen equivalent Pm(1)Pm8Ho4 cuboctahedra, faces with four equivalent Pm(2)Pm8Ho4 cuboctahedra, faces with six equivalent Ho(1)Pm12 cuboctahedra, and faces with eight equivalent Pm(1)Pm8Ho4 cuboctahedra.