Materials Data on Tb2HfAl9 by Materials Project

Abstract

Tb2HfAl9 is Uranium Silicide-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Tb is bonded to twelve Al atoms to form TbAl12 cuboctahedra that share corners with four equivalent HfAl12 cuboctahedra, corners with eight equivalent TbAl12 cuboctahedra, edges with twenty AlHf4Al8 cuboctahedra, a faceface with one HfAl12 cuboctahedra, faces with five equivalent TbAl12 cuboctahedra, and faces with eight AlTb2Hf2Al8 cuboctahedra. There are a spread of Tb–Al bond distances ranging from 2.98–3.02 Å. Hf is bonded to twelve Al atoms to form HfAl12 cuboctahedra that share corners with four equivalent HfAl12 cuboctahedra, corners with eight equivalent TbAl12 cuboctahedra, edges with sixteen equivalent AlTb2Hf2Al8 cuboctahedra, faces with two equivalent TbAl12 cuboctahedra, faces with four equivalent HfAl12 cuboctahedra, and faces with twelve AlHf4Al8 cuboctahedra. There are eight shorter (2.90 Å) and four longer (2.98 Å) Hf–Al bond lengths. There are four inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Hf and eight equivalent Al atoms to form AlHf4Al8 cuboctahedra that share corners with four equivalent AlHf4Al8 cuboctahedra, edges with eight equivalent TbAl12 cuboctahedra, edges with sixteen equivalent AlTb2Hf2Al8 cuboctahedra, faces with four equivalent HfAl12 cuboctahedra, and faces with twelve AlHf4Al8 cuboctahedra. All Al–Al bond lengths are 2.90 Å. In the second Al site, Al is bonded in a distorted rectangular see-saw-like geometry to four equivalent Tb and eight Al atoms. There are four shorter (2.99 Å) and four longer (3.05 Å) Al–Al bond lengths. In the third 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 twelve AlTb2Hf2Al8 cuboctahedra, edges with four equivalent TbAl12 cuboctahedra, edges with four equivalent HfAl12 cuboctahedra, edges with twelve AlHf4Al8 cuboctahedra, faces with two equivalent TbAl12 cuboctahedra, faces with two equivalent HfAl12 cuboctahedra, and faces with twelve AlHf4Al8 cuboctahedra. All Al–Al bond lengths are 2.98 Å. In the fourth Al site, Al is bonded to four equivalent Tb and eight Al atoms to form distorted AlTb4Al8 cuboctahedra that share corners with twelve AlTb2Hf2Al8 cuboctahedra, edges with eight equivalent TbAl12 cuboctahedra, edges with eight equivalent AlTb2Hf2Al8 cuboctahedra, faces with four equivalent TbAl12 cuboctahedra, and faces with ten AlTb2Hf2Al8 cuboctahedra. All Al–Al bond lengths are 2.98 Å.