Pr is alpha Samarium structured and crystallizes in the trigonal R-3m space group. There are four inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to six equivalent Pr(1) and six equivalent Pr(2) atoms to form a mixture of edge, face, and corner-sharing PrPr12 cuboctahedra. In the second Pr site, Pr(2) is bonded to three equivalent Pr(1) and nine equivalent Pr(2) atoms to form a mixture of edge, face, and corner-sharing PrPr12 cuboctahedra. In the third Pr site, Pr(2) is bonded to three equivalent Pr(1) and nine Pr(2,2) atoms to form a mixture of edge, face, and corner-sharing PrPr12 cuboctahedra. In the fourth Pr site, Pr(2) is bonded to three equivalent Pr(1) and nine Pr(2,2) atoms to form a mixture of edge, face, and corner-sharing PrPr12 cuboctahedra.
Pr is alpha Samarium structured and crystallizes in the trigonal R-3m space group. There are four inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to six equivalent Pr(1) and six equivalent Pr(2) atoms to form a mixture of edge, face, and corner-sharing PrPr12 cuboctahedra. All Pr(1)-Pr(1) bond lengths are 3.76 Å. All Pr(1)-Pr(2) bond lengths are 3.69 Å. In the second Pr site, Pr(2) is bonded to three equivalent Pr(1) and nine equivalent Pr(2) atoms to form a mixture of edge, face, and corner-sharing PrPr12 cuboctahedra. There are three shorter (3.73 Å) and six longer (3.76 Å) Pr(2)-Pr(2) bond lengths. In the third Pr site, Pr(2) is bonded to three equivalent Pr(1) and nine Pr(2,2) atoms to form a mixture of edge, face, and corner-sharing PrPr12 cuboctahedra. All Pr(2)-Pr(1) bond lengths are 3.69 Å. There are three shorter (3.73 Å) and six longer (3.76 Å) Pr(2)-Pr(2,2) bond lengths. In the fourth Pr site, Pr(2) is bonded to three equivalent Pr(1) and nine Pr(2,2) atoms to form a mixture of edge, face, and corner-sharing PrPr12 cuboctahedra. All Pr(2)-Pr(1) bond lengths are 3.69 Å. All Pr(2)-Pr(2) bond lengths are 3.76 Å.