LiMg4Os2H13 crystallizes in the hexagonal P6_3/mmc space group. Li(1) is bonded in a 6-coordinate geometry to six equivalent H(2) atoms. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to one H(3), three equivalent H(1), and six equivalent H(2) atoms. In the second Mg site, Mg(2) is bonded to three equivalent H(2) and nine equivalent H(1) atoms to form MgH12 cuboctahedra that share corners with six equivalent Mg(2)H12 cuboctahedra, faces with three equivalent Mg(2)H12 cuboctahedra, and faces with four equivalent Os(1)H6 octahedra. Os(1) is bonded to three equivalent H(1) and three equivalent H(2) atoms to form OsH6 octahedra that share faces with four equivalent Mg(2)H12 cuboctahedra. There are three inequivalent H sites. In the first H site, H(3) is bonded in a linear geometry to two equivalent Mg(1) atoms. In the second H site, H(1) is bonded to one Mg(1), three equivalent Mg(2), and one Os(1) atom to form a mixture of edge, face, and corner-sharing HMg4Os square pyramids. In the third H site, H(2) is bonded in a 5-coordinate geometry to one Li(1), one Mg(2), two equivalent Mg(1), and one Os(1) atom.
LiMg4Os2H13 crystallizes in the hexagonal P6_3/mmc space group. Li(1) is bonded in a 6-coordinate geometry to six equivalent H(2) atoms. All Li(1)-H(2) bond lengths are 2.13 Å. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to one H(3), three equivalent H(1), and six equivalent H(2) atoms. The Mg(1)-H(3) bond length is 1.87 Å. All Mg(1)-H(1) bond lengths are 2.25 Å. All Mg(1)-H(2) bond lengths are 2.37 Å. In the second Mg site, Mg(2) is bonded to three equivalent H(2) and nine equivalent H(1) atoms to form MgH12 cuboctahedra that share corners with six equivalent Mg(2)H12 cuboctahedra, faces with three equivalent Mg(2)H12 cuboctahedra, and faces with four equivalent Os(1)H6 octahedra. All Mg(2)-H(2) bond lengths are 2.44 Å. All Mg(2)-H(1) bond lengths are 2.36 Å. Os(1) is bonded to three equivalent H(1) and three equivalent H(2) atoms to form OsH6 octahedra that share faces with four equivalent Mg(2)H12 cuboctahedra. All Os(1)-H(1) bond lengths are 1.70 Å. All Os(1)-H(2) bond lengths are 1.70 Å. There are three inequivalent H sites. In the first H site, H(3) is bonded in a linear geometry to two equivalent Mg(1) atoms. In the second H site, H(1) is bonded to one Mg(1), three equivalent Mg(2), and one Os(1) atom to form a mixture of edge, face, and corner-sharing HMg4Os square pyramids. In the third H site, H(2) is bonded in a 5-coordinate geometry to one Li(1), one Mg(2), two equivalent Mg(1), and one Os(1) atom.