Materials Data on Ti2NiH by Materials Project

Abstract

Ti2NiH crystallizes in the cubic Fd-3m space group. The structure is three-dimensional and consists of one Ti2H framework and one Ti2Ni4H framework. In the Ti2H framework, Ti is bonded in a 7-coordinate geometry to three H atoms. There are two shorter (2.15 Å) and one longer (2.17 Å) Ti–H bond lengths. There are two inequivalent H sites. In the first H site, H is bonded to six equivalent Ti atoms to form face-sharing HTi6 octahedra. In the second H site, H is bonded to six equivalent Ti atoms to form a mixture of corner and face-sharing HTi6 octahedra. The corner-sharing octahedral tilt angles are 40°. In the Ti2Ni4H framework, Ti is bonded to six equivalent Ni and two equivalent H atoms to form distorted TiNi6H2 hexagonal bipyramids that share faces with six equivalent TiNi6H2 hexagonal bipyramids and faces with two equivalent HTi4Ni4 tetrahedra. All Ti–Ni bond lengths are 2.52 Å. Both Ti–H bond lengths are 2.48 Å. Ni is bonded in a distorted single-bond geometry to three equivalent Ti and one H atom. The Ni–H bond length is 1.79 Å. H is bonded to four equivalent Ti and four equivalent Ni atoms to form HTi4Ni4 tetrahedra that share corners with four equivalent HTi4Ni4 tetrahedra and faces with four equivalent TiNi6H2 hexagonal bipyramids.