UFe3Al9 crystallizes in the monoclinic C2/m space group. U(1) is bonded in a 20-coordinate geometry to two equivalent Fe(1), four equivalent Fe(2), two equivalent Al(3), four equivalent Al(2), and eight equivalent Al(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 10-coordinate geometry to two equivalent U(1), two equivalent Al(3), four equivalent Al(1), and four equivalent Al(2) atoms. In the second Fe site, Fe(2) is bonded in a 10-coordinate geometry to two equivalent U(1), two equivalent Fe(2), four equivalent Al(1), and four equivalent Al(2) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a 12-coordinate geometry to two equivalent U(1), one Fe(1), two equivalent Fe(2), one Al(3), two equivalent Al(1), and four equivalent Al(2) atoms. In the second Al site, Al(2) is bonded in a 10-coordinate geometry to one U(1), one Fe(1), two equivalent Fe(2), one Al(2), one Al(3), and four equivalent Al(1) atoms. In the third Al site, Al(3) is bonded in a distorted linear geometry to two equivalent U(1), two equivalent Fe(1), four equivalent Al(1), and four equivalent Al(2) atoms.
UFe3Al9 crystallizes in the monoclinic C2/m space group. U(1) is bonded in a 20-coordinate geometry to two equivalent Fe(1), four equivalent Fe(2), two equivalent Al(3), four equivalent Al(2), and eight equivalent Al(1) atoms. Both U(1)-Fe(1) bond lengths are 3.36 Å. All U(1)-Fe(2) bond lengths are 3.37 Å. Both U(1)-Al(3) bond lengths are 3.33 Å. All U(1)-Al(2) bond lengths are 3.05 Å. There are four shorter (3.14 Å) and four longer (3.19 Å) U(1)-Al(1) bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 10-coordinate geometry to two equivalent U(1), two equivalent Al(3), four equivalent Al(1), and four equivalent Al(2) atoms. Both Fe(1)-Al(3) bond lengths are 2.51 Å. All Fe(1)-Al(1) bond lengths are 2.55 Å. All Fe(1)-Al(2) bond lengths are 2.72 Å. In the second Fe site, Fe(2) is bonded in a 10-coordinate geometry to two equivalent U(1), two equivalent Fe(2), four equivalent Al(1), and four equivalent Al(2) atoms. Both Fe(2)-Fe(2) bond lengths are 2.51 Å. There are two shorter (2.50 Å) and two longer (2.53 Å) Fe(2)-Al(1) bond lengths. There are two shorter (2.58 Å) and two longer (2.65 Å) Fe(2)-Al(2) bond lengths. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a 12-coordinate geometry to two equivalent U(1), one Fe(1), two equivalent Fe(2), one Al(3), two equivalent Al(1), and four equivalent Al(2) atoms. The Al(1)-Al(3) bond length is 2.62 Å. There is one shorter (2.66 Å) and one longer (2.81 Å) Al(1)-Al(1) bond length. There are a spread of Al(1)-Al(2) bond distances ranging from 2.65-2.89 Å. In the second Al site, Al(2) is bonded in a 10-coordinate geometry to one U(1), one Fe(1), two equivalent Fe(2), one Al(2), one Al(3), and four equivalent Al(1) atoms. The Al(2)-Al(2) bond length is 2.72 Å. The Al(2)-Al(3) bond length is 2.75 Å. In the third Al site, Al(3) is bonded in a distorted linear geometry to two equivalent U(1), two equivalent Fe(1), four equivalent Al(1), and four equivalent Al(2) atoms.