EuAu2Al2 crystallizes in the tetragonal P4/nmm space group. Eu(1) is bonded in a 16-coordinate geometry to four equivalent Au(1), four equivalent Au(2), four equivalent Al(1), and four equivalent Al(2) atoms. There are two inequivalent Au sites. In the first Au site, Au(1) is bonded in a 5-coordinate geometry to four equivalent Eu(1), one Al(1), and four equivalent Al(2) atoms. In the second Au site, Au(2) is bonded to four equivalent Eu(1) and four equivalent Al(1) atoms to form distorted AuEu4Al4 tetrahedra that share corners with twelve equivalent Al(2)Eu4Au4 tetrahedra, edges with two equivalent Al(2)Eu4Au4 tetrahedra, edges with four equivalent Au(2)Eu4Al4 tetrahedra, and faces with four equivalent Au(2)Eu4Al4 tetrahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 5-coordinate geometry to four equivalent Eu(1), one Au(1), and four equivalent Au(2) atoms. In the second Al site, Al(2) is bonded to four equivalent Eu(1) and four equivalent Au(1) atoms to form distorted AlEu4Au4 tetrahedra that share corners with twelve equivalent Au(2)Eu4Al4 tetrahedra, edges with two equivalent Au(2)Eu4Al4 tetrahedra, edges with four equivalent Al(2)Eu4Au4 tetrahedra, and faces with four equivalent Al(2)Eu4Au4 tetrahedra.
EuAu2Al2 crystallizes in the tetragonal P4/nmm space group. Eu(1) is bonded in a 16-coordinate geometry to four equivalent Au(1), four equivalent Au(2), four equivalent Al(1), and four equivalent Al(2) atoms. All Eu(1)-Au(1) bond lengths are 3.38 Å. All Eu(1)-Au(2) bond lengths are 3.42 Å. All Eu(1)-Al(1) bond lengths are 3.38 Å. All Eu(1)-Al(2) bond lengths are 3.44 Å. There are two inequivalent Au sites. In the first Au site, Au(1) is bonded in a 5-coordinate geometry to four equivalent Eu(1), one Al(1), and four equivalent Al(2) atoms. The Au(1)-Al(1) bond length is 2.53 Å. All Au(1)-Al(2) bond lengths are 2.60 Å. In the second Au site, Au(2) is bonded to four equivalent Eu(1) and four equivalent Al(1) atoms to form distorted AuEu4Al4 tetrahedra that share corners with twelve equivalent Al(2)Eu4Au4 tetrahedra, edges with two equivalent Al(2)Eu4Au4 tetrahedra, edges with four equivalent Au(2)Eu4Al4 tetrahedra, and faces with four equivalent Au(2)Eu4Al4 tetrahedra. All Au(2)-Al(1) bond lengths are 2.59 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 5-coordinate geometry to four equivalent Eu(1), one Au(1), and four equivalent Au(2) atoms. In the second Al site, Al(2) is bonded to four equivalent Eu(1) and four equivalent Au(1) atoms to form distorted AlEu4Au4 tetrahedra that share corners with twelve equivalent Au(2)Eu4Al4 tetrahedra, edges with two equivalent Au(2)Eu4Al4 tetrahedra, edges with four equivalent Al(2)Eu4Au4 tetrahedra, and faces with four equivalent Al(2)Eu4Au4 tetrahedra.