Materials Data on Tb4HfAl15 by Materials Project

Abstract

Tb4HfAl15 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Tb sites. In the first Tb site, Tb is bonded to twelve Al atoms to form TbAl12 cuboctahedra that share corners with six equivalent AlTb2Hf2Al8 cuboctahedra, corners with nine TbAl12 cuboctahedra, a faceface with one HfAl12 cuboctahedra, and faces with six TbAl12 cuboctahedra. There are a spread of Tb–Al bond distances ranging from 3.02–3.06 Å. In the second Tb site, Tb is bonded to twelve Al atoms to form TbAl12 cuboctahedra that share corners with twelve TbAl12 cuboctahedra, edges with six equivalent AlTb2Hf2Al8 cuboctahedra, faces with three equivalent TbAl12 cuboctahedra, faces with three equivalent HfAl12 cuboctahedra, and faces with three equivalent AlTb2Hf2Al8 cuboctahedra. There are a spread of Tb–Al bond distances ranging from 2.97–3.03 Å. Hf is bonded to twelve Al atoms to form HfAl12 cuboctahedra that share corners with six equivalent HfAl12 cuboctahedra, edges with six equivalent AlTb2Hf2Al8 cuboctahedra, faces with six equivalent AlTb2Hf2Al8 cuboctahedra, and faces with eight TbAl12 cuboctahedra. There are six shorter (2.99 Å) and six longer (3.03 Å) Hf–Al bond lengths. There are three inequivalent Al sites. In the first Al site, Al is bonded to two equivalent Tb, two equivalent Hf, and eight Al atoms to form distorted AlTb2Hf2Al8 cuboctahedra that share corners with four equivalent TbAl12 cuboctahedra, corners with six equivalent AlTb2Hf2Al8 cuboctahedra, edges with two equivalent HfAl12 cuboctahedra, edges with four equivalent TbAl12 cuboctahedra, edges with four equivalent AlTb2Hf2Al8 cuboctahedra, faces with two equivalent TbAl12 cuboctahedra, faces with two equivalent HfAl12 cuboctahedra, and faces with four equivalent AlTb2Hf2Al8 cuboctahedra. There are four shorter (2.86 Å) and four longer (3.03 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a distorted square co-planar geometry to four Tb and two equivalent Al atoms. Both Al–Al bond lengths are 3.00 Å. In the third Al site, Al is bonded in a 4-coordinate geometry to three Tb, one Hf, and six Al atoms. Both Al–Al bond lengths are 2.77 Å.