PrMg12 crystallizes in the tetragonal I4/mmm space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), four equivalent Mg(2), four equivalent Mg(3), and two equivalent Pr(1) atoms to form a mixture of distorted corner, edge, and face-sharing MgPr2Mg10 cuboctahedra. In the second Mg site, Mg(3) is bonded in a distorted q6 geometry to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Pr(1) atoms. In the third Mg site, Mg(2) is bonded in a 10-coordinate geometry to one Mg(2), four equivalent Mg(1), four equivalent Mg(3), and one Pr(1) atom. Pr(1) is bonded in a 20-coordinate geometry to four equivalent Mg(2), eight equivalent Mg(1), and eight equivalent Mg(3) atoms.
PrMg12 crystallizes in the tetragonal I4/mmm space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), four equivalent Mg(2), four equivalent Mg(3), and two equivalent Pr(1) atoms to form a mixture of distorted corner, edge, and face-sharing MgPr2Mg10 cuboctahedra. Both Mg(1)-Mg(1) bond lengths are 2.95 Å. All Mg(1)-Mg(2) bond lengths are 3.14 Å. All Mg(1)-Mg(3) bond lengths are 2.98 Å. Both Mg(1)-Pr(1) bond lengths are 3.91 Å. In the second Mg site, Mg(3) is bonded in a distorted q6 geometry to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Pr(1) atoms. Both Mg(3)-Mg(3) bond lengths are 3.07 Å. There are two shorter (3.28 Å) and two longer (3.31 Å) Mg(3)-Mg(2) bond lengths. Both Mg(3)-Pr(1) bond lengths are 3.66 Å. In the third Mg site, Mg(2) is bonded in a 10-coordinate geometry to one Mg(2), four equivalent Mg(1), four equivalent Mg(3), and one Pr(1) atom. The Mg(2)-Mg(2) bond length is 3.02 Å. The Mg(2)-Pr(1) bond length is 3.61 Å. Pr(1) is bonded in a 20-coordinate geometry to four equivalent Mg(2), eight equivalent Mg(1), and eight equivalent Mg(3) atoms.