Mg5Pt crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 2-coordinate geometry to three equivalent Mg(2) and two equivalent Pt(1) atoms. In the second Mg site, Mg(2) is bonded to two equivalent Mg(2), four equivalent Mg(3), and six equivalent Mg(1) atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 2-coordinate geometry to two equivalent Mg(2) and two equivalent Pt(1) atoms. Pt(1) is bonded in a body-centered cubic geometry to four equivalent Mg(1) and four equivalent Mg(3) atoms.
Mg5Pt crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 2-coordinate geometry to three equivalent Mg(2) and two equivalent Pt(1) atoms. There are two shorter (3.11 Å) and one longer (3.35 Å) Mg(1)-Mg(2) bond length. Both Mg(1)-Pt(1) bond lengths are 2.80 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(2), four equivalent Mg(3), and six equivalent Mg(1) atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. Both Mg(2)-Mg(2) bond lengths are 3.33 Å. All Mg(2)-Mg(3) bond lengths are 3.03 Å. In the third Mg site, Mg(3) is bonded in a 2-coordinate geometry to two equivalent Mg(2) and two equivalent Pt(1) atoms. Both Mg(3)-Pt(1) bond lengths are 2.71 Å. Pt(1) is bonded in a body-centered cubic geometry to four equivalent Mg(1) and four equivalent Mg(3) atoms.