FeAl2P2(HO)18 crystallizes in the triclinic P-1 space group. Fe(1) is bonded to two equivalent O(3), two equivalent O(7), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with two equivalent Al(2)O6 octahedra and corners with four equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. In the second Al site, Al(2) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form AlO6 octahedra that share corners with two equivalent Al(1)O6 octahedra and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-52°. There are nine inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(4) and one O(6) atom. In the third H site, H(3) is bonded in a distorted linear geometry to one O(6) and one O(9) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(7) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(7) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(1) and one O(8) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(3) and one O(8) atom. In the eighth H site, H(8) is bonded in a distorted single-bond geometry to one O(3) and one O(9) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(9) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Al(1), one P(1), and one H(6) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Al(2) and one P(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Fe(1), one P(1), one H(7), and one H(8) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Al(1), one P(1), and one H(2) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Al(1), one Al(2), and one H(1) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one Al(2), one H(2), and one H(3) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Fe(1), one H(4), and one H(5) atom. In the eighth O site, O(8) is bonded in a distorted water-like geometry to one Fe(1), one H(6), and one H(7) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one H(3), one H(8), and one H(9) atom.
FeAl2P2(HO)18 crystallizes in the triclinic P-1 space group. Fe(1) is bonded to two equivalent O(3), two equivalent O(7), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra. Both Fe(1)-O(3) bond lengths are 2.20 Å. Both Fe(1)-O(7) bond lengths are 2.16 Å. Both Fe(1)-O(8) bond lengths are 2.10 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with two equivalent Al(2)O6 octahedra and corners with four equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. Both Al(1)-O(1) bond lengths are 1.94 Å. Both Al(1)-O(4) bond lengths are 1.95 Å. Both Al(1)-O(5) bond lengths are 1.91 Å. In the second Al site, Al(2) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form AlO6 octahedra that share corners with two equivalent Al(1)O6 octahedra and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. Both Al(2)-O(2) bond lengths are 1.91 Å. Both Al(2)-O(5) bond lengths are 1.89 Å. Both Al(2)-O(6) bond lengths are 1.98 Å. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-52°. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(4) bond length is 1.56 Å. There are nine inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.99 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(4) and one O(6) atom. The H(2)-O(4) bond length is 1.68 Å. The H(2)-O(6) bond length is 1.01 Å. In the third H site, H(3) is bonded in a distorted linear geometry to one O(6) and one O(9) atom. The H(3)-O(6) bond length is 1.02 Å. The H(3)-O(9) bond length is 1.61 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(7) atom. The H(4)-O(7) bond length is 0.97 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(7) atom. The H(5)-O(7) bond length is 0.99 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(1) and one O(8) atom. The H(6)-O(1) bond length is 1.72 Å. The H(6)-O(8) bond length is 0.99 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(3) and one O(8) atom. The H(7)-O(3) bond length is 1.76 Å. The H(7)-O(8) bond length is 0.99 Å. In the eighth H site, H(8) is bonded in a distorted single-bond geometry to one O(3) and one O(9) atom. The H(8)-O(3) bond length is 1.67 Å. The H(8)-O(9) bond length is 1.01 Å. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(9) atom. The H(9)-O(9) bond length is 0.98 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Al(1), one P(1), and one H(6) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Al(2) and one P(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Fe(1), one P(1), one H(7), and one H(8) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Al(1), one P(1), and one H(2) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Al(1), one Al(2), and one H(1) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one Al(2), one H(2), and one H(3) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Fe(1), one H(4), and one H(5) atom. In the eighth O site, O(8) is bonded in a distorted water-like geometry to one Fe(1), one H(6), and one H(7) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one H(3), one H(8), and one H(9) atom.