Materials Data on Mg2NiH4 by Materials Project

Mg2NiH4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Mg sites. In the first Mg site, Mg is bonded in a 7-coordinate geometry to seven H atoms. There are a spread of Mg–H bond distances ranging from 2.07–2.36 Å. In the second Mg site, Mg is bonded in a 4-coordinate geometry to four H atoms. There are two shorter (2.13 Å) and two longer (2.15 Å) Mg–H bond lengths. In the third Mg site, Mg is bonded in a 6-coordinate geometry to six H atoms. There are a spread of Mg–H bond distances ranging from 2.03–2.25 Å. Ni is bonded in a tetrahedral geometry to four H atoms. There are a spread of Ni–H bond distances ranging from 1.55–1.58 Å. There are four inequivalent H sites. In the first H site, H is bonded in a distorted see-saw-like geometry to three Mg and one Ni atom. In the second H site, H is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Ni atom. In the third H site, H is bonded in a distorted see-saw-like geometry to three equivalent Mg and one Ni atom. In the fourth H site, H is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Ni atom.