Mg3Pm is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to eight Mg(1,1) and four equivalent Pm(1) atoms. In the second Mg site, Mg(1) is bonded in a 12-coordinate geometry to eight equivalent Mg(1) and four equivalent Pm(1) atoms. Pm(1) is bonded to twelve Mg(1,1) atoms to form a mixture of corner and face-sharing PmMg12 cuboctahedra.
Mg3Pm is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to eight Mg(1,1) and four equivalent Pm(1) atoms. There are a spread of Mg(1)-Mg(1,1) bond distances ranging from 3.21-3.51 Å. There are two shorter (3.29 Å) and two longer (3.39 Å) Mg(1)-Pm(1) bond lengths. In the second Mg site, Mg(1) is bonded in a 12-coordinate geometry to eight equivalent Mg(1) and four equivalent Pm(1) atoms. There are two shorter (3.29 Å) and two longer (3.39 Å) Mg(1)-Pm(1) bond lengths. Pm(1) is bonded to twelve Mg(1,1) atoms to form a mixture of corner and face-sharing PmMg12 cuboctahedra.