Materials Data on CaMgNiH4 by Materials Project

Abstract

CaMgNiH4 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. Ca is bonded in a hexagonal planar geometry to six H atoms. There are three shorter (2.45 Å) and three longer (2.52 Å) Ca–H bond lengths. Mg is bonded in a 6-coordinate geometry to six equivalent H atoms. There are three shorter (2.10 Å) and three longer (2.15 Å) Mg–H bond lengths. Ni is bonded in a tetrahedral geometry to four H atoms. All Ni–H bond lengths are 1.59 Å. There are two inequivalent H sites. In the first H site, H is bonded in a distorted rectangular see-saw-like geometry to one Ca, two equivalent Mg, and one Ni atom. In the second H site, H is bonded to three equivalent Ca and one Ni atom to form corner-sharing HCa3Ni trigonal pyramids.