Materials Data on HoAlCu4 by Materials Project

Abstract

HoCu4Al crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Ho is bonded in a 6-coordinate geometry to fifteen Cu and three equivalent Al atoms. There are three shorter (2.98 Å) and twelve longer (3.27 Å) Ho–Cu bond lengths. All Ho–Al bond lengths are 2.98 Å. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded to three equivalent Ho, six equivalent Cu, and three equivalent Al atoms to form CuHo3Al3Cu6 cuboctahedra that share corners with nine equivalent AlHo3Cu9 cuboctahedra, corners with twelve equivalent CuHo4Al2Cu6 cuboctahedra, edges with six equivalent CuHo3Al3Cu6 cuboctahedra, faces with three equivalent AlHo3Cu9 cuboctahedra, and faces with twenty CuHo3Al3Cu6 cuboctahedra. All Cu–Cu bond lengths are 2.49 Å. All Cu–Al bond lengths are 2.98 Å. In the second Cu site, Cu is bonded to four equivalent Ho, six Cu, and two equivalent Al atoms to form distorted CuHo4Al2Cu6 cuboctahedra that share corners with four equivalent AlHo3Cu9 cuboctahedra, corners with twenty CuHo3Al3Cu6 cuboctahedra, edges with ten equivalent CuHo4Al2Cu6 cuboctahedra, faces with six equivalent AlHo3Cu9 cuboctahedra, and faces with sixteen CuHo3Al3Cu6 cuboctahedra. There are two shorter (2.56 Å) and two longer (2.60 Å) Cu–Cu bond lengths. Both Cu–Al bond lengths are 2.50 Å. Al is bonded to three equivalent Ho and nine Cu atoms to form distorted AlHo3Cu9 cuboctahedra that share corners with twenty-one CuHo3Al3Cu6 cuboctahedra, edges with six equivalent AlHo3Cu9 cuboctahedra, faces with two equivalent AlHo3Cu9 cuboctahedra, and faces with twenty-one CuHo3Al3Cu6 cuboctahedra.