PmY3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Pm(1) is bonded to twelve Y(1,1) atoms to form PmY12 cuboctahedra that share corners with six equivalent Pm(1)Y12 cuboctahedra; corners with twelve Y(1,1)Pm4Y8 cuboctahedra; edges with eighteen Y(1,1)Pm4Y8 cuboctahedra; faces with eight equivalent Pm(1)Y12 cuboctahedra; and faces with twelve Y(1,1)Pm4Y8 cuboctahedra. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to four equivalent Pm(1) and eight Y(1,1) atoms to form YPm4Y8 cuboctahedra that share corners with four equivalent Pm(1)Y12 cuboctahedra; corners with fourteen equivalent Y(1)Pm4Y8 cuboctahedra; edges with six equivalent Pm(1)Y12 cuboctahedra; edges with twelve Y(1,1)Pm4Y8 cuboctahedra; faces with four equivalent Pm(1)Y12 cuboctahedra; and faces with sixteen Y(1,1)Pm4Y8 cuboctahedra. In the second Y site, Y(1) is bonded to four equivalent Pm(1) and eight equivalent Y(1) atoms to form YPm4Y8 cuboctahedra that share corners with four equivalent Pm(1)Y12 cuboctahedra; corners with fourteen Y(1,1)Pm4Y8 cuboctahedra; edges with six equivalent Pm(1)Y12 cuboctahedra; edges with twelve equivalent Y(1)Pm4Y8 cuboctahedra; faces with four equivalent Pm(1)Y12 cuboctahedra; and faces with sixteen Y(1,1)Pm4Y8 cuboctahedra.
PmY3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Pm(1) is bonded to twelve Y(1,1) atoms to form PmY12 cuboctahedra that share corners with six equivalent Pm(1)Y12 cuboctahedra; corners with twelve Y(1,1)Pm4Y8 cuboctahedra; edges with eighteen Y(1,1)Pm4Y8 cuboctahedra; faces with eight equivalent Pm(1)Y12 cuboctahedra; and faces with twelve Y(1,1)Pm4Y8 cuboctahedra. There are six shorter (3.63 Å) and six longer (3.67 Å) Pm(1)-Y(1,1) bond lengths. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to four equivalent Pm(1) and eight Y(1,1) atoms to form YPm4Y8 cuboctahedra that share corners with four equivalent Pm(1)Y12 cuboctahedra; corners with fourteen equivalent Y(1)Pm4Y8 cuboctahedra; edges with six equivalent Pm(1)Y12 cuboctahedra; edges with twelve Y(1,1)Pm4Y8 cuboctahedra; faces with four equivalent Pm(1)Y12 cuboctahedra; and faces with sixteen Y(1,1)Pm4Y8 cuboctahedra. There are a spread of Y(1)-Y(1,1) bond distances ranging from 3.62-3.69 Å. In the second Y site, Y(1) is bonded to four equivalent Pm(1) and eight equivalent Y(1) atoms to form YPm4Y8 cuboctahedra that share corners with four equivalent Pm(1)Y12 cuboctahedra; corners with fourteen Y(1,1)Pm4Y8 cuboctahedra; edges with six equivalent Pm(1)Y12 cuboctahedra; edges with twelve equivalent Y(1)Pm4Y8 cuboctahedra; faces with four equivalent Pm(1)Y12 cuboctahedra; and faces with sixteen Y(1,1)Pm4Y8 cuboctahedra.