DOI: 10.17188/1753036
title: Materials Data on La2Al3Cu7 by Materials Project

description: La2Cu7Al3 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. La is bonded in a 6-coordinate geometry to twelve Cu and six Al atoms. There are a spread of La–Cu bond distances ranging from 3.01–3.37 Å. There are a spread of La–Al bond distances ranging from 3.34–3.39 Å. There are five inequivalent Cu sites. In the first Cu site, Cu is bonded in a 12-coordinate geometry to three equivalent La, two equivalent Cu, and four Al atoms. Both Cu–Cu bond lengths are 2.58 Å. There are two shorter (2.60 Å) and two longer (2.62 Å) Cu–Al bond lengths. In the second Cu site, Cu is bonded in a 12-coordinate geometry to three equivalent La, four Cu, and two equivalent Al atoms. There are two shorter (2.58 Å) and two longer (2.59 Å) Cu–Cu bond lengths. Both Cu–Al bond lengths are 2.56 Å. In the third Cu site, Cu is bonded to four equivalent La, six Cu, and two equivalent Al atoms to form distorted CuLa4Al2Cu6 cuboctahedra that share corners with six CuLa4Al2Cu6 cuboctahedra, corners with ten AlLa4AlCu7 cuboctahedra, edges with four equivalent CuLa4Al2Cu6 cuboctahedra, edges with six AlLa4AlCu7 cuboctahedra, faces with four equivalent AlLa4AlCu7 cuboctahedra, and faces with six CuLa4Al2Cu6 cuboctahedra. Both Cu–Cu bond lengths are 2.63 Å. Both Cu–Al bond lengths are 2.58 Å. In the fourth Cu site, Cu is bonded to four equivalent La, four equivalent Cu, and four Al atoms to form distorted CuLa4Al4Cu4 cuboctahedra that share corners with four equivalent AlLa4AlCu7 cuboctahedra, corners with twelve CuLa4Al2Cu6 cuboctahedra, edges with two equivalent CuLa4Al2Cu6 cuboctahedra, edges with eight AlLa4AlCu7 cuboctahedra, faces with four CuLa4Al2Cu6 cuboctahedra, and faces with six AlLa4AlCu7 cuboctahedra. There are two shorter (2.63 Å) and two longer (2.64 Å) Cu–Al bond lengths. In the fifth Cu site, Cu is bonded to four equivalent La, six Cu, and two equivalent Al atoms to form distorted CuLa4Al2Cu6 cuboctahedra that share corners with eight CuLa4Al4Cu4 cuboctahedra, corners with eight AlLa4AlCu7 cuboctahedra, edges with four equivalent AlLa4AlCu7 cuboctahedra, edges with six CuLa4Al2Cu6 cuboctahedra, faces with four CuLa4Al2Cu6 cuboctahedra, and faces with six AlLa4AlCu7 cuboctahedra. Both Cu–Al bond lengths are 2.58 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent La, seven Cu, and one Al atom to form distorted AlLa4AlCu7 cuboctahedra that share corners with six CuLa4Al2Cu6 cuboctahedra, corners with ten AlLa4AlCu7 cuboctahedra, edges with four AlLa4AlCu7 cuboctahedra, edges with six CuLa4Al2Cu6 cuboctahedra, faces with four AlLa4AlCu7 cuboctahedra, and faces with six CuLa4Al2Cu6 cuboctahedra. The Al–Al bond length is 2.69 Å. In the second Al site, Al is bonded to four equivalent La, six Cu, and two equivalent Al atoms to form distorted AlLa4Al2Cu6 cuboctahedra that share corners with six AlLa4AlCu7 cuboctahedra, corners with ten CuLa4Al2Cu6 cuboctahedra, edges with four equivalent AlLa4AlCu7 cuboctahedra, edges with six CuLa4Al2Cu6 cuboctahedra, faces with four CuLa4Al4Cu4 cuboctahedra, and faces with six AlLa4AlCu7 cuboctahedra.