Materials Data on TiFeH2 by Materials Project

Abstract

TiFeH2 crystallizes in the orthorhombic Pmc2_1 space group. The structure is three-dimensional. Ti is bonded in a 6-coordinate geometry to six H atoms. There are a spread of Ti–H bond distances ranging from 1.89–2.07 Å. Fe is bonded to four H atoms to form distorted corner-sharing FeH4 trigonal pyramids. There are a spread of Fe–H bond distances ranging from 1.69–2.00 Å. There are two inequivalent H sites. In the first H site, H is bonded to two equivalent Ti and two equivalent Fe atoms to form distorted HTi2Fe2 tetrahedra that share corners with eight equivalent HTi4Fe2 octahedra, corners with four equivalent HTi2Fe2 tetrahedra, and edges with two equivalent HTi4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 44–81°. In the second H site, H is bonded to four equivalent Ti and two equivalent Fe atoms to form HTi4Fe2 octahedra that share corners with four equivalent HTi4Fe2 octahedra, corners with eight equivalent HTi2Fe2 tetrahedra, edges with two equivalent HTi4Fe2 octahedra, edges with two equivalent HTi2Fe2 tetrahedra, and faces with two equivalent HTi4Fe2 octahedra. The corner-sharing octahedral tilt angles are 55°.