PmSc3 is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. Pm(1) is bonded to four equivalent Sc(2) and eight equivalent Sc(1) atoms to form PmSc12 cuboctahedra that share corners with four equivalent Pm(1)Sc12 cuboctahedra, corners with eight equivalent Sc(2)Pm4Sc8 cuboctahedra, edges with eight equivalent Pm(1)Sc12 cuboctahedra, edges with sixteen equivalent Sc(1)Pm4Sc8 cuboctahedra, faces with four equivalent Pm(1)Sc12 cuboctahedra, faces with six equivalent Sc(2)Pm4Sc8 cuboctahedra, and faces with eight equivalent Sc(1)Pm4Sc8 cuboctahedra. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to four equivalent Pm(1), four equivalent Sc(1), and four equivalent Sc(2) atoms to form distorted ScPm4Sc8 cuboctahedra that share corners with twelve equivalent Sc(1)Pm4Sc8 cuboctahedra, edges with eight equivalent Pm(1)Sc12 cuboctahedra, edges with eight equivalent Sc(1)Pm4Sc8 cuboctahedra, edges with eight equivalent Sc(2)Pm4Sc8 cuboctahedra, faces with four equivalent Pm(1)Sc12 cuboctahedra, faces with four equivalent Sc(2)Pm4Sc8 cuboctahedra, and faces with ten equivalent Sc(1)Pm4Sc8 cuboctahedra. In the second Sc site, Sc(2) is bonded to four equivalent Pm(1) and eight equivalent Sc(1) atoms to form ScPm4Sc8 cuboctahedra that share corners with four equivalent Sc(2)Pm4Sc8 cuboctahedra, corners with eight equivalent Pm(1)Sc12 cuboctahedra, edges with eight equivalent Sc(2)Pm4Sc8 cuboctahedra, edges with sixteen equivalent Sc(1)Pm4Sc8 cuboctahedra, faces with four equivalent Sc(2)Pm4Sc8 cuboctahedra, faces with six equivalent Pm(1)Sc12 cuboctahedra, and faces with eight equivalent Sc(1)Pm4Sc8 cuboctahedra.
PmSc3 is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. Pm(1) is bonded to four equivalent Sc(2) and eight equivalent Sc(1) atoms to form PmSc12 cuboctahedra that share corners with four equivalent Pm(1)Sc12 cuboctahedra, corners with eight equivalent Sc(2)Pm4Sc8 cuboctahedra, edges with eight equivalent Pm(1)Sc12 cuboctahedra, edges with sixteen equivalent Sc(1)Pm4Sc8 cuboctahedra, faces with four equivalent Pm(1)Sc12 cuboctahedra, faces with six equivalent Sc(2)Pm4Sc8 cuboctahedra, and faces with eight equivalent Sc(1)Pm4Sc8 cuboctahedra. All Pm(1)-Sc(2) bond lengths are 3.46 Å. All Pm(1)-Sc(1) bond lengths are 3.34 Å. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to four equivalent Pm(1), four equivalent Sc(1), and four equivalent Sc(2) atoms to form distorted ScPm4Sc8 cuboctahedra that share corners with twelve equivalent Sc(1)Pm4Sc8 cuboctahedra, edges with eight equivalent Pm(1)Sc12 cuboctahedra, edges with eight equivalent Sc(1)Pm4Sc8 cuboctahedra, edges with eight equivalent Sc(2)Pm4Sc8 cuboctahedra, faces with four equivalent Pm(1)Sc12 cuboctahedra, faces with four equivalent Sc(2)Pm4Sc8 cuboctahedra, and faces with ten equivalent Sc(1)Pm4Sc8 cuboctahedra. All Sc(1)-Sc(1) bond lengths are 3.46 Å. All Sc(1)-Sc(2) bond lengths are 3.34 Å. In the second Sc site, Sc(2) is bonded to four equivalent Pm(1) and eight equivalent Sc(1) atoms to form ScPm4Sc8 cuboctahedra that share corners with four equivalent Sc(2)Pm4Sc8 cuboctahedra, corners with eight equivalent Pm(1)Sc12 cuboctahedra, edges with eight equivalent Sc(2)Pm4Sc8 cuboctahedra, edges with sixteen equivalent Sc(1)Pm4Sc8 cuboctahedra, faces with four equivalent Sc(2)Pm4Sc8 cuboctahedra, faces with six equivalent Pm(1)Sc12 cuboctahedra, and faces with eight equivalent Sc(1)Pm4Sc8 cuboctahedra.