NdAl11O18 crystallizes in the triclinic P-1 space group. Nd(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(7) atoms. There are six inequivalent Al sites. In the first Al site, Al(1) is bonded in a 2-coordinate geometry to one O(3) and one O(5) atom. In the second Al site, Al(2) is bonded in a distorted linear geometry to two equivalent O(4) and two equivalent O(8) atoms. In the third Al site, Al(3) is bonded in a 3-coordinate geometry to one O(1), one O(2), and one O(5) atom. In the fourth Al site, Al(4) is bonded in a distorted linear geometry to one O(4), one O(6), and one O(9) atom. In the fifth Al site, Al(5) is bonded in a 4-coordinate geometry to one O(3), one O(8), and two equivalent O(4) atoms. In the sixth Al site, Al(6) is bonded in a distorted single-bond geometry to one O(5), one O(9), and two equivalent O(7) atoms. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Al(3) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Nd(1) and one Al(3) atom. In the third O site, O(3) is bonded in an L-shaped geometry to one Al(1) and one Al(5) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Al(2), one Al(4), and two equivalent Al(5) atoms. In the fifth O site, O(5) is bonded in a distorted water-like geometry to one Al(1), one Al(3), and one Al(6) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Al(4) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Nd(1) and two equivalent Al(6) atoms. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Al(2) and one Al(5) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to one Al(4) and one Al(6) atom.
NdAl11O18 crystallizes in the triclinic P-1 space group. Nd(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(7) atoms. Both Nd(1)-O(2) bond lengths are 2.57 Å. Both Nd(1)-O(7) bond lengths are 2.21 Å. There are six inequivalent Al sites. In the first Al site, Al(1) is bonded in a 2-coordinate geometry to one O(3) and one O(5) atom. The Al(1)-O(3) bond length is 1.52 Å. The Al(1)-O(5) bond length is 1.28 Å. In the second Al site, Al(2) is bonded in a distorted linear geometry to two equivalent O(4) and two equivalent O(8) atoms. Both Al(2)-O(4) bond lengths are 2.23 Å. Both Al(2)-O(8) bond lengths are 1.35 Å. In the third Al site, Al(3) is bonded in a 3-coordinate geometry to one O(1), one O(2), and one O(5) atom. The Al(3)-O(1) bond length is 1.55 Å. The Al(3)-O(2) bond length is 1.33 Å. The Al(3)-O(5) bond length is 1.97 Å. In the fourth Al site, Al(4) is bonded in a distorted linear geometry to one O(4), one O(6), and one O(9) atom. The Al(4)-O(4) bond length is 1.38 Å. The Al(4)-O(6) bond length is 1.31 Å. The Al(4)-O(9) bond length is 2.19 Å. In the fifth Al site, Al(5) is bonded in a 4-coordinate geometry to one O(3), one O(8), and two equivalent O(4) atoms. The Al(5)-O(3) bond length is 1.39 Å. The Al(5)-O(8) bond length is 2.22 Å. There is one shorter (1.88 Å) and one longer (2.09 Å) Al(5)-O(4) bond length. In the sixth Al site, Al(6) is bonded in a distorted single-bond geometry to one O(5), one O(9), and two equivalent O(7) atoms. The Al(6)-O(5) bond length is 1.27 Å. The Al(6)-O(9) bond length is 2.51 Å. There is one shorter (2.13 Å) and one longer (2.48 Å) Al(6)-O(7) bond length. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Al(3) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Nd(1) and one Al(3) atom. In the third O site, O(3) is bonded in an L-shaped geometry to one Al(1) and one Al(5) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Al(2), one Al(4), and two equivalent Al(5) atoms. In the fifth O site, O(5) is bonded in a distorted water-like geometry to one Al(1), one Al(3), and one Al(6) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Al(4) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Nd(1) and two equivalent Al(6) atoms. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Al(2) and one Al(5) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to one Al(4) and one Al(6) atom.