Al11Cr4 is beta Plutonium-derived structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 10-coordinate geometry to one Al(2), one Al(4), two equivalent Al(6), three equivalent Al(1), and three equivalent Al(5) atoms. In the second Cr site, Cr(2) is bonded in a 10-coordinate geometry to one Al(1), one Al(3), one Al(5), one Al(6), three equivalent Al(2), and three equivalent Al(4) atoms. There are six inequivalent Al sites. In the first Al site, Al(1) is bonded in a 8-coordinate geometry to one Cr(2), three equivalent Cr(1), one Al(2), one Al(4), one Al(5), and two equivalent Al(6) atoms. In the second Al site, Al(2) is bonded in a 11-coordinate geometry to one Cr(1), three equivalent Cr(2), one Al(1), one Al(2), one Al(5), two equivalent Al(3), and two equivalent Al(4) atoms. In the third Al site, Al(3) is bonded to two equivalent Cr(2), two equivalent Al(6), four equivalent Al(2), and four equivalent Al(4) atoms to form distorted edge-sharing AlAl10Cr2 cuboctahedra. In the fourth Al site, Al(4) is bonded in a 12-coordinate geometry to one Cr(1), three equivalent Cr(2), one Al(1), one Al(4), one Al(5), one Al(6), two equivalent Al(2), and two equivalent Al(3) atoms. In the fifth Al site, Al(5) is bonded in a 10-coordinate geometry to one Cr(2), three equivalent Cr(1), one Al(1), one Al(2), one Al(4), one Al(5), and two equivalent Al(6) atoms. In the sixth Al site, Al(6) is bonded in a 8-coordinate geometry to one Cr(2), two equivalent Cr(1), one Al(3), one Al(4), two equivalent Al(1), and two equivalent Al(5) atoms.
Al11Cr4 is beta Plutonium-derived structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 10-coordinate geometry to one Al(2), one Al(4), two equivalent Al(6), three equivalent Al(1), and three equivalent Al(5) atoms. The Cr(1)-Al(2) bond length is 2.76 Å. The Cr(1)-Al(4) bond length is 2.79 Å. There is one shorter (2.47 Å) and one longer (2.88 Å) Cr(1)-Al(6) bond length. There are a spread of Cr(1)-Al(1) bond distances ranging from 2.54-2.68 Å. There are a spread of Cr(1)-Al(5) bond distances ranging from 2.61-2.75 Å. In the second Cr site, Cr(2) is bonded in a 10-coordinate geometry to one Al(1), one Al(3), one Al(5), one Al(6), three equivalent Al(2), and three equivalent Al(4) atoms. The Cr(2)-Al(1) bond length is 2.54 Å. The Cr(2)-Al(3) bond length is 2.46 Å. The Cr(2)-Al(5) bond length is 2.59 Å. The Cr(2)-Al(6) bond length is 2.56 Å. There are a spread of Cr(2)-Al(2) bond distances ranging from 2.56-2.74 Å. There are a spread of Cr(2)-Al(4) bond distances ranging from 2.57-2.78 Å. There are six inequivalent Al sites. In the first Al site, Al(1) is bonded in a 8-coordinate geometry to one Cr(2), three equivalent Cr(1), one Al(2), one Al(4), one Al(5), and two equivalent Al(6) atoms. The Al(1)-Al(2) bond length is 2.63 Å. The Al(1)-Al(4) bond length is 2.92 Å. The Al(1)-Al(5) bond length is 2.72 Å. There is one shorter (2.67 Å) and one longer (2.70 Å) Al(1)-Al(6) bond length. In the second Al site, Al(2) is bonded in a 11-coordinate geometry to one Cr(1), three equivalent Cr(2), one Al(1), one Al(2), one Al(5), two equivalent Al(3), and two equivalent Al(4) atoms. The Al(2)-Al(2) bond length is 2.69 Å. The Al(2)-Al(5) bond length is 2.94 Å. There is one shorter (2.89 Å) and one longer (2.92 Å) Al(2)-Al(3) bond length. There is one shorter (2.88 Å) and one longer (2.96 Å) Al(2)-Al(4) bond length. In the third Al site, Al(3) is bonded to two equivalent Cr(2), two equivalent Al(6), four equivalent Al(2), and four equivalent Al(4) atoms to form distorted edge-sharing AlAl10Cr2 cuboctahedra. Both Al(3)-Al(6) bond lengths are 2.74 Å. There are two shorter (2.86 Å) and two longer (2.90 Å) Al(3)-Al(4) bond lengths. In the fourth Al site, Al(4) is bonded in a 12-coordinate geometry to one Cr(1), three equivalent Cr(2), one Al(1), one Al(4), one Al(5), one Al(6), two equivalent Al(2), and two equivalent Al(3) atoms. The Al(4)-Al(4) bond length is 2.69 Å. The Al(4)-Al(5) bond length is 2.66 Å. The Al(4)-Al(6) bond length is 3.08 Å. In the fifth Al site, Al(5) is bonded in a 10-coordinate geometry to one Cr(2), three equivalent Cr(1), one Al(1), one Al(2), one Al(4), one Al(5), and two equivalent Al(6) atoms. The Al(5)-Al(5) bond length is 2.68 Å. There is one shorter (2.63 Å) and one longer (2.73 Å) Al(5)-Al(6) bond length. In the sixth Al site, Al(6) is bonded in a 8-coordinate geometry to one Cr(2), two equivalent Cr(1), one Al(3), one Al(4), two equivalent Al(1), and two equivalent Al(5) atoms.