DOI: 10.17188/1743194
title: Materials Data on Ho4HfAl15 by Materials Project

description: Ho4HfAl15 is Uranium Silicide-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded to twelve Al atoms to form HoAl12 cuboctahedra that share corners with four equivalent HfAl12 cuboctahedra, corners with eight HoAl12 cuboctahedra, edges with twenty-four AlHo2Hf2Al8 cuboctahedra, a faceface with one HfAl12 cuboctahedra, faces with five HoAl12 cuboctahedra, and faces with twelve AlHo4Al8 cuboctahedra. There are a spread of Ho–Al bond distances ranging from 2.98–3.01 Å. In the second Ho site, Ho is bonded to twelve Al atoms to form HoAl12 cuboctahedra that share corners with twelve HoAl12 cuboctahedra, edges with twenty-four AlHo4Al8 cuboctahedra, faces with six HoAl12 cuboctahedra, and faces with twelve AlHo4Al8 cuboctahedra. There are a spread of Ho–Al bond distances ranging from 2.98–3.00 Å. Hf is bonded to twelve Al atoms to form HfAl12 cuboctahedra that share corners with four equivalent HfAl12 cuboctahedra, corners with eight equivalent HoAl12 cuboctahedra, edges with twenty-four AlHo2Hf2Al8 cuboctahedra, faces with two equivalent HoAl12 cuboctahedra, faces with four equivalent HfAl12 cuboctahedra, and faces with twelve AlHo2Hf2Al8 cuboctahedra. There are eight shorter (2.91 Å) and four longer (2.98 Å) Hf–Al bond lengths. There are six 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 twelve AlHf4Al8 cuboctahedra, edges with eight equivalent HoAl12 cuboctahedra, edges with sixteen equivalent AlHo2Hf2Al8 cuboctahedra, faces with four equivalent HfAl12 cuboctahedra, and faces with fourteen AlHo2Hf2Al8 cuboctahedra. All Al–Al bond lengths are 2.91 Å. In the second Al site, Al is bonded to four equivalent Ho and eight Al atoms to form distorted AlHo4Al8 cuboctahedra that share corners with twelve AlHf4Al8 cuboctahedra, edges with four equivalent HoAl12 cuboctahedra, edges with four equivalent HfAl12 cuboctahedra, edges with sixteen AlHo2Hf2Al8 cuboctahedra, faces with four equivalent HoAl12 cuboctahedra, and faces with fourteen AlHf4Al8 cuboctahedra. There are four shorter (2.99 Å) and four longer (3.02 Å) Al–Al bond lengths. In the third Al site, Al is bonded to four equivalent Ho and eight Al atoms to form distorted AlHo4Al8 cuboctahedra that share corners with twelve AlHo4Al8 cuboctahedra, edges with eight HoAl12 cuboctahedra, edges with sixteen AlHo4Al8 cuboctahedra, faces with four equivalent HoAl12 cuboctahedra, and faces with fourteen AlHo4Al8 cuboctahedra. All Al–Al bond lengths are 2.99 Å. In the fourth Al site, Al is bonded to two equivalent Ho, two equivalent Hf, and eight Al atoms to form distorted AlHo2Hf2Al8 cuboctahedra that share corners with twelve AlHo2Hf2Al8 cuboctahedra, edges with four equivalent HoAl12 cuboctahedra, edges with four equivalent HfAl12 cuboctahedra, edges with sixteen AlHf4Al8 cuboctahedra, faces with two equivalent HoAl12 cuboctahedra, faces with two equivalent HfAl12 cuboctahedra, and faces with fourteen AlHf4Al8 cuboctahedra. All Al–Al bond lengths are 2.98 Å. In the fifth Al site, Al is bonded to four Ho and eight Al atoms to form distorted AlHo4Al8 cuboctahedra that share corners with twelve AlHo2Hf2Al8 cuboctahedra, edges with eight HoAl12 cuboctahedra, edges with sixteen AlHo4Al8 cuboctahedra, faces with four HoAl12 cuboctahedra, and faces with fourteen AlHo4Al8 cuboctahedra. All Al–Al bond lengths are 2.98 Å. In the sixth Al site, Al is bonded to four equivalent Ho and eight Al atoms to form distorted AlHo4Al8 cuboctahedra that share corners with twelve AlHo4Al8 cuboctahedra, edges with eight equivalent HoAl12 cuboctahedra, edges with sixteen AlHo4Al8 cuboctahedra, faces with four equivalent HoAl12 cuboctahedra, and faces with fourteen AlHo4Al8 cuboctahedra. All Al–Al bond lengths are 2.98 Å.