U3(FeAl3)4 crystallizes in the hexagonal P6_3/mmc space group. U(1) is bonded in a 15-coordinate geometry to four equivalent Fe(1), one Al(4), two equivalent Al(1), two equivalent Al(3), and six equivalent Al(2) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(2) is bonded in a body-centered cubic geometry to two equivalent Al(4) and six equivalent Al(2) atoms. In the second Fe site, Fe(1) is bonded in a 8-coordinate geometry to four equivalent U(1), two equivalent Al(1), two equivalent Al(3), and four equivalent Al(2) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a 12-coordinate geometry to three equivalent U(1), three equivalent Fe(1), three equivalent Al(2), and three equivalent Al(3) atoms. In the second Al site, Al(2) is bonded in a 3-coordinate geometry to three equivalent U(1), one Fe(2), two equivalent Fe(1), and one Al(1) atom. In the third Al site, Al(3) is bonded in a 2-coordinate geometry to two equivalent U(1), two equivalent Fe(1), and two equivalent Al(1) atoms. In the fourth Al site, Al(4) is bonded in a distorted linear geometry to three equivalent U(1) and two equivalent Fe(2) atoms.
U3(FeAl3)4 crystallizes in the hexagonal P6_3/mmc space group. U(1) is bonded in a 15-coordinate geometry to four equivalent Fe(1), one Al(4), two equivalent Al(1), two equivalent Al(3), and six equivalent Al(2) atoms. All U(1)-Fe(1) bond lengths are 3.24 Å. The U(1)-Al(4) bond length is 3.04 Å. Both U(1)-Al(1) bond lengths are 3.00 Å. Both U(1)-Al(3) bond lengths are 3.00 Å. There are two shorter (3.08 Å) and four longer (3.18 Å) U(1)-Al(2) bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe(2) is bonded in a body-centered cubic geometry to two equivalent Al(4) and six equivalent Al(2) atoms. Both Fe(2)-Al(4) bond lengths are 2.28 Å. All Fe(2)-Al(2) bond lengths are 2.50 Å. In the second Fe site, Fe(1) is bonded in a 8-coordinate geometry to four equivalent U(1), two equivalent Al(1), two equivalent Al(3), and four equivalent Al(2) atoms. Both Fe(1)-Al(1) bond lengths are 2.52 Å. Both Fe(1)-Al(3) bond lengths are 2.47 Å. All Fe(1)-Al(2) bond lengths are 2.69 Å. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a 12-coordinate geometry to three equivalent U(1), three equivalent Fe(1), three equivalent Al(2), and three equivalent Al(3) atoms. All Al(1)-Al(2) bond lengths are 2.76 Å. All Al(1)-Al(3) bond lengths are 2.82 Å. In the second Al site, Al(2) is bonded in a 3-coordinate geometry to three equivalent U(1), one Fe(2), two equivalent Fe(1), and one Al(1) atom. In the third Al site, Al(3) is bonded in a 2-coordinate geometry to two equivalent U(1), two equivalent Fe(1), and two equivalent Al(1) atoms. In the fourth Al site, Al(4) is bonded in a distorted linear geometry to three equivalent U(1) and two equivalent Fe(2) atoms.