DOE OSTI2020
CeAg3Al2 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. Ce is bonded in a 6-coordinate geometry to ten Ag and eight equivalent Al atoms. There are a spread of Ce–Ag bond distances ranging from 3.12–3.57 Å. All Ce–Al bond lengths are 3.59 Å. There are two inequivalent Ag sites. In the first Ag site, Ag is bonded to four equivalent Ce, four equivalent Ag, and four equivalent Al atoms to form distorted AgCe4Al4Ag4 cuboctahedra that share corners with eight equivalent AgCe4Al4Ag4 cuboctahedra, corners with eight equivalent AlCe4Al2Ag6 cuboctahedra, edges with two equivalent AgCe4Al4Ag4 cuboctahedra, edges with eight equivalent AlCe4Al2Ag6 cuboctahedra, faces with two equivalent AgCe4Al4Ag4 cuboctahedra, and faces with eight equivalent AlCe4Al2Ag6 cuboctahedra. All Ag–Ag bond lengths are 2.84 Å. All Ag–Al bond lengths are 2.77 Å. In the second Ag site, Ag is bonded in a 12-coordinate geometry to three equivalent Ce, two equivalent Ag, and four equivalent Al atoms. All Ag–Al bond lengths are 2.76 Å. Al is bonded to four equivalent Ce, six Ag, and two equivalent Al atoms to form distorted AlCe4Al2Ag6 cuboctahedra that share corners with four equivalent AgCe4Al4Ag4 cuboctahedra, corners with twelve equivalent AlCe4Al2Ag6 cuboctahedra, edges with four equivalent AgCe4Al4Ag4 cuboctahedra, edges with six equivalent AlCe4Al2Ag6 cuboctahedra, faces with four equivalent AgCe4Al4Ag4 cuboctahedra, and faces with six equivalent AlCe4Al2Ag6 cuboctahedra. Both Al–Al bond lengths are 2.74 Å.