Materials Data on LiMg4H13Os2 by Materials Project

Abstract

LiMg4Os2H13 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Li1+ is bonded in a 6-coordinate geometry to six equivalent H+0.38- atoms. All Li–H bond lengths are 2.13 Å. There are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a 1-coordinate geometry to ten H+0.38- atoms. There are a spread of Mg–H bond distances ranging from 1.87–2.37 Å. In the second Mg2+ site, Mg2+ is bonded to twelve H+0.38- atoms to form MgH12 cuboctahedra that share corners with six equivalent MgH12 cuboctahedra, faces with three equivalent MgH12 cuboctahedra, and faces with four equivalent OsH6 octahedra. There are nine shorter (2.36 Å) and three longer (2.44 Å) Mg–H bond lengths. Os2- is bonded to six H+0.38- atoms to form OsH6 octahedra that share faces with four equivalent MgH12 cuboctahedra. All Os–H bond lengths are 1.70 Å. There are three inequivalent H+0.38- sites. In the first H+0.38- site, H+0.38- is bonded in a linear geometry to two equivalent Mg2+ atoms. In the second H+0.38- site, H+0.38- is bonded to four Mg2+ and one Os2- atom to form a mixture of edge, face, and corner-sharing HMg4Os square pyramids. In the third H+0.38- site, H+0.38- is bonded in a 5-coordinate geometry to one Li1+, three Mg2+, and one Os2- atom.