Pm is alpha Samarium structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to six equivalent Pm(1) and six equivalent Pm(2) atoms to form a mixture of face, corner, and edge-sharing PmPm12 cuboctahedra. In the second Pm site, Pm(2) is bonded to three equivalent Pm(1) and nine equivalent Pm(2) atoms to form a mixture of face, corner, and edge-sharing PmPm12 cuboctahedra.
Pm is alpha Samarium structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to six equivalent Pm(1) and six equivalent Pm(2) atoms to form a mixture of face, corner, and edge-sharing PmPm12 cuboctahedra. All Pm(1)-Pm(1) bond lengths are 3.70 Å. All Pm(1)-Pm(2) bond lengths are 3.63 Å. In the second Pm site, Pm(2) is bonded to three equivalent Pm(1) and nine equivalent Pm(2) atoms to form a mixture of face, corner, and edge-sharing PmPm12 cuboctahedra. There are three shorter (3.63 Å) and six longer (3.70 Å) Pm(2)-Pm(2) bond lengths.