The compound described by MgAl2P2(HO)18 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(7) atoms to form MgO6 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(5), two equivalent O(6), and two equivalent O(9) 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 44°. In the second Al site, Al(2) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(8) 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 44°. P(1) is bonded to one O(6), one O(7), one O(8), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(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 41-51°. There are nine inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(2) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(2) and one O(9) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(1) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(1) atom. In the seventh H site, H(7) is bonded in a distorted single-bond geometry to one O(3) and one O(4) atom. In the eighth H site, H(8) is bonded in a distorted single-bond geometry to one O(4) and one O(6) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(5) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one Mg(1), one H(5), and one H(6) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one H(3), and one H(4) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to one H(1), one H(2), and one H(7) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one Al(2), one H(7), and one H(8) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Al(1), one Al(2), and one H(9) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Al(1), one P(1), and one H(8) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Mg(1) and one P(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Al(2) and one P(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Al(1), one P(1), and one H(4) atom. is represented by the CIF card [CIF]
data_MgAl2P2(HO)18
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.270
_cell_length_b   6.975
_cell_length_c   10.295
_cell_angle_alpha   96.683
_cell_angle_beta   101.765
_cell_angle_gamma   110.277
_symmetry_Int_Tables_number   1
_cell_volume   340.234
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Mg  Mg0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.500  0.000  0.500  1.0
  Al  Al2  1  0.500  0.500  0.500  1.0
  P  P3  1  0.985  0.078  0.333  1.0
  P  P4  1  0.015  0.922  0.667  1.0
  H  H5  1  0.919  0.423  0.748  1.0
  H  H6  1  0.081  0.577  0.252  1.0
  H  H7  1  0.096  0.658  0.821  1.0
  H  H8  1  0.904  0.342  0.179  1.0
  H  H9  1  0.527  0.989  0.123  1.0
  H  H10  1  0.699  0.058  0.794  1.0
  H  H11  1  0.198  0.397  0.951  1.0
  H  H12  1  0.802  0.603  0.049  1.0
  H  H13  1  0.339  0.403  0.103  1.0
  H  H14  1  0.661  0.597  0.897  1.0
  H  H15  1  0.685  0.506  0.277  1.0
  H  H16  1  0.315  0.494  0.723  1.0
  H  H17  1  0.608  0.700  0.326  1.0
  H  H18  1  0.393  0.300  0.674  1.0
  H  H19  1  0.832  0.326  0.486  1.0
  H  H20  1  0.168  0.674  0.514  1.0
  H  H21  1  0.473  0.011  0.877  1.0
  H  H22  1  0.301  0.942  0.206  1.0
  O  O23  1  0.259  0.313  0.013  1.0
  O  O24  1  0.678  0.063  0.888  1.0
  O  O25  1  0.322  0.937  0.112  1.0
  O  O26  1  0.901  0.486  0.189  1.0
  O  O27  1  0.099  0.514  0.811  1.0
  O  O28  1  0.458  0.458  0.684  1.0
  O  O29  1  0.644  0.290  0.503  1.0
  O  O30  1  0.356  0.710  0.497  1.0
  O  O31  1  0.712  0.955  0.372  1.0
  O  O32  1  0.288  0.045  0.628  1.0
  O  O33  1  0.097  0.906  0.818  1.0
  O  O34  1  0.903  0.094  0.182  1.0
  O  O35  1  0.875  0.701  0.575  1.0
  O  O36  1  0.125  0.299  0.425  1.0
  O  O37  1  0.814  0.041  0.651  1.0
  O  O38  1  0.186  0.959  0.349  1.0
  O  O39  1  0.741  0.687  0.987  1.0
  O  O40  1  0.542  0.542  0.316  1.0
[/CIF]
.
The compound described by MgAl2P2(HO)18 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(7) atoms to form MgO6 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(5), two equivalent O(6), and two equivalent O(9) 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 44°. In the second Al site, Al(2) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(8) 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 44°. P(1) is bonded to one O(6), one O(7), one O(8), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(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 41-51°. There are nine inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(2) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(2) and one O(9) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(1) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(1) atom. In the seventh H site, H(7) is bonded in a distorted single-bond geometry to one O(3) and one O(4) atom. In the eighth H site, H(8) is bonded in a distorted single-bond geometry to one O(4) and one O(6) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(5) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one Mg(1), one H(5), and one H(6) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one H(3), and one H(4) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to one H(1), one H(2), and one H(7) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one Al(2), one H(7), and one H(8) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Al(1), one Al(2), and one H(9) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Al(1), one P(1), and one H(8) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Mg(1) and one P(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Al(2) and one P(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Al(1), one P(1), and one H(4) atom. is represented by the CIF card [CIF]
data_MgAl2P2(HO)18
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.270
_cell_length_b   6.975
_cell_length_c   10.295
_cell_angle_alpha   96.683
_cell_angle_beta   101.765
_cell_angle_gamma   110.277
_symmetry_Int_Tables_number   1
_cell_volume   340.234
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Mg  Mg0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.500  0.000  0.500  1.0
  Al  Al2  1  0.500  0.500  0.500  1.0
  P  P3  1  0.985  0.078  0.333  1.0
  P  P4  1  0.015  0.922  0.667  1.0
  H  H5  1  0.919  0.423  0.748  1.0
  H  H6  1  0.081  0.577  0.252  1.0
  H  H7  1  0.096  0.658  0.821  1.0
  H  H8  1  0.904  0.342  0.179  1.0
  H  H9  1  0.527  0.989  0.123  1.0
  H  H10  1  0.699  0.058  0.794  1.0
  H  H11  1  0.198  0.397  0.951  1.0
  H  H12  1  0.802  0.603  0.049  1.0
  H  H13  1  0.339  0.403  0.103  1.0
  H  H14  1  0.661  0.597  0.897  1.0
  H  H15  1  0.685  0.506  0.277  1.0
  H  H16  1  0.315  0.494  0.723  1.0
  H  H17  1  0.608  0.700  0.326  1.0
  H  H18  1  0.393  0.300  0.674  1.0
  H  H19  1  0.832  0.326  0.486  1.0
  H  H20  1  0.168  0.674  0.514  1.0
  H  H21  1  0.473  0.011  0.877  1.0
  H  H22  1  0.301  0.942  0.206  1.0
  O  O23  1  0.259  0.313  0.013  1.0
  O  O24  1  0.678  0.063  0.888  1.0
  O  O25  1  0.322  0.937  0.112  1.0
  O  O26  1  0.901  0.486  0.189  1.0
  O  O27  1  0.099  0.514  0.811  1.0
  O  O28  1  0.458  0.458  0.684  1.0
  O  O29  1  0.644  0.290  0.503  1.0
  O  O30  1  0.356  0.710  0.497  1.0
  O  O31  1  0.712  0.955  0.372  1.0
  O  O32  1  0.288  0.045  0.628  1.0
  O  O33  1  0.097  0.906  0.818  1.0
  O  O34  1  0.903  0.094  0.182  1.0
  O  O35  1  0.875  0.701  0.575  1.0
  O  O36  1  0.125  0.299  0.425  1.0
  O  O37  1  0.814  0.041  0.651  1.0
  O  O38  1  0.186  0.959  0.349  1.0
  O  O39  1  0.741  0.687  0.987  1.0
  O  O40  1  0.542  0.542  0.316  1.0
[/CIF]
.