Materials Data on PrAlCu4 by Materials Project
PrCu4Al crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Pr is bonded in a 6-coordinate geometry to fifteen Cu and three equivalent Al atoms. There are three shorter (3.08 Å) and twelve longer (3.35 Å) Pr–Cu bond lengths. All Pr–Al bond lengths are 3.08 Å. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded to three equivalent Pr, six equivalent Cu, and three equivalent Al atoms to form distorted CuPr3Al3Cu6 cuboctahedra that share corners with twelve equivalent CuPr4Al2Cu6 cuboctahedra, edges with six equivalent CuPr3Al3Cu6 cuboctahedra, and faces with twenty CuPr3Al3Cu6 cuboctahedra. All Cu–Cu bond lengths are 2.53 Å. All Cu–Al bond lengths are 3.08 Å. In the second Cu site, Cu is bonded to four equivalent Pr, six Cu, and two equivalent Al atoms to form distorted CuPr4Al2Cu6 cuboctahedra that share corners with twenty CuPr3Al3Cu6 cuboctahedra, edges with ten equivalent CuPr4Al2Cu6 cuboctahedra, and faces with sixteen CuPr3Al3Cu6 cuboctahedra. There are two shorter (2.66 Å) and two longer (2.69 Å) Cu–Cu bond lengths. Both Cu–Al bond lengths are 2.54 Å. Al is bonded in a 12-coordinate geometry to three equivalent Pr and nine Cu atoms.