Materials Data on TmAlCu4 by Materials Project

Abstract

TmCu4Al crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Tm is bonded in a 6-coordinate geometry to fifteen Cu and three equivalent Al atoms. There are three shorter (2.95 Å) and twelve longer (3.26 Å) Tm–Cu bond lengths. All Tm–Al bond lengths are 2.95 Å. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded to three equivalent Tm, six equivalent Cu, and three equivalent Al atoms to form CuTm3Al3Cu6 cuboctahedra that share corners with nine equivalent AlTm3Cu9 cuboctahedra, corners with twelve equivalent CuTm4Al2Cu6 cuboctahedra, edges with six equivalent CuTm3Al3Cu6 cuboctahedra, faces with three equivalent AlTm3Cu9 cuboctahedra, and faces with twenty CuTm3Al3Cu6 cuboctahedra. All Cu–Cu bond lengths are 2.50 Å. All Cu–Al bond lengths are 2.95 Å. In the second Cu site, Cu is bonded to four equivalent Tm, six Cu, and two equivalent Al atoms to form distorted CuTm4Al2Cu6 cuboctahedra that share corners with four equivalent AlTm3Cu9 cuboctahedra, corners with twenty CuTm3Al3Cu6 cuboctahedra, edges with ten equivalent CuTm4Al2Cu6 cuboctahedra, faces with six equivalent AlTm3Cu9 cuboctahedra, and faces with sixteen CuTm3Al3Cu6 cuboctahedra. There are two shorter (2.55 Å) and two longer (2.57 Å) Cu–Cu bond lengths. Both Cu–Al bond lengths are 2.50 Å. Al is bonded to three equivalent Tm and nine Cu atoms to form distorted AlTm3Cu9 cuboctahedra that share corners with twenty-one CuTm3Al3Cu6 cuboctahedra, edges with six equivalent AlTm3Cu9 cuboctahedra, faces with two equivalent AlTm3Cu9 cuboctahedra, and faces with twenty-one CuTm3Al3Cu6 cuboctahedra.