Materials Data on Tb4H9 by Materials Project
Tb4H9 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are four inequivalent Tb sites. In the first Tb site, Tb is bonded in a distorted body-centered cubic geometry to ten H atoms. There are eight shorter (2.28 Å) and two longer (2.61 Å) Tb–H bond lengths. In the second Tb site, Tb is bonded in a distorted body-centered cubic geometry to ten H atoms. There are eight shorter (2.28 Å) and two longer (2.61 Å) Tb–H bond lengths. In the third Tb site, Tb is bonded in a distorted body-centered cubic geometry to nine H atoms. There are a spread of Tb–H bond distances ranging from 2.22–2.60 Å. In the fourth Tb site, Tb is bonded in a distorted body-centered cubic geometry to ten H atoms. There are eight shorter (2.28 Å) and two longer (2.61 Å) Tb–H bond lengths. There are two inequivalent H sites. In the first H site, H is bonded to four Tb atoms to form HTb4 tetrahedra that share corners with three equivalent HTb6 octahedra, corners with sixteen equivalent HTb4 tetrahedra, edges with six equivalent HTb4 tetrahedra, and a faceface with one HTb6 octahedra. The corner-sharing octahedra tilt angles range from 54–56°. In the second H site, H is bonded to six Tb atoms to form HTb6 octahedra that share corners with four equivalent HTb6 octahedra, corners with twenty-four equivalent HTb4 tetrahedra, and faces with eight equivalent HTb4 tetrahedra. The corner-sharing octahedral tilt angles are 0°.