Materials Data on LiMgAlH6 by Materials Project

Abstract

LiMgAlH6 is Hydrophilite-derived structured and crystallizes in the trigonal P321 space group. The structure is three-dimensional. Li1+ is bonded to six H1- atoms to form LiH6 octahedra that share corners with two equivalent AlH6 octahedra, corners with six equivalent MgH6 octahedra, and edges with two equivalent AlH6 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Li–H bond distances ranging from 1.86–1.99 Å. Mg2+ is bonded to six H1- atoms to form MgH6 octahedra that share corners with four equivalent AlH6 octahedra, corners with six equivalent LiH6 octahedra, and an edgeedge with one AlH6 octahedra. The corner-sharing octahedra tilt angles range from 48–55°. There are a spread of Mg–H bond distances ranging from 1.92–1.99 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six equivalent H1- atoms to form AlH6 octahedra that share corners with six equivalent LiH6 octahedra and edges with three equivalent MgH6 octahedra. The corner-sharing octahedral tilt angles are 53°. All Al–H bond lengths are 1.74 Å. In the second Al3+ site, Al3+ is bonded to six H1- atoms to form AlH6 octahedra that share corners with six equivalent MgH6 octahedra and edges with three equivalent LiH6 octahedra. The corner-sharing octahedra tilt angles range from 48–50°. All Al–H bond lengths are 1.75 Å. There are three inequivalent H1- sites. In the first H1- site, H1- is bonded in a trigonal planar geometry to one Li1+, one Mg2+, and one Al3+ atom. In the second H1- site, H1- is bonded in a distorted trigonal planar geometry to one Li1+, one Mg2+, and one Al3+ atom. In the third H1- site, H1- is bonded in a trigonal planar geometry to one Li1+, one Mg2+, and one Al3+ atom.