The structure described by MgAl4(HO)12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one H(10), one O(1), one O(11), one O(6), and one O(7) atom to form MgHO4 trigonal bipyramids that share corners with two equivalent Al(3)O6 octahedra,  a cornercorner with one Al(2)O5 trigonal bipyramid, corners with two equivalent Al(4)O5 trigonal bipyramids, and  an edgeedge with one Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-52°. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(12), one O(4), one O(7), one O(8), and one O(9) atom to form AlO6 octahedra that share edges with two equivalent Al(3)O6 octahedra,  an edgeedge with one Mg(1)HO4 trigonal bipyramid, and  an edgeedge with one Al(2)O5 trigonal bipyramid. In the second Al site, Al(2) is bonded to one O(10), one O(2), one O(3), one O(7), and one O(8) atom to form AlO5 trigonal bipyramids that share  a cornercorner with one Mg(1)HO4 trigonal bipyramid, corners with two equivalent Al(4)O5 trigonal bipyramids, and  an edgeedge with one Al(1)O6 octahedra. In the third Al site, Al(3) is bonded to one O(1), one O(12), one O(4), one O(5), one O(6), and one O(9) atom to form AlO6 octahedra that share corners with two equivalent Mg(1)HO4 trigonal bipyramids, edges with two equivalent Al(1)O6 octahedra, and  an edgeedge with one Al(4)O5 trigonal bipyramid. In the fourth Al site, Al(4) is bonded to one O(10), one O(11), one O(3), one O(5), and one O(6) atom to form distorted AlO5 trigonal bipyramids that share corners with two equivalent Mg(1)HO4 trigonal bipyramids, corners with two equivalent Al(2)O5 trigonal bipyramids, and  an edgeedge with one Al(3)O6 octahedra. There are twelve inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(2) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(3) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(4) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(5) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(6) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(7) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(8) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(9) atom. In the tenth H site, H(10) is bonded in a single-bond geometry to one Mg(1) atom. In the eleventh H site, H(11) is bonded in a single-bond geometry to one O(11) atom. In the twelfth H site, H(12) is bonded in a single-bond geometry to one O(12) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Mg(1), one Al(1), one Al(3), and one H(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Al(2) and one H(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Al(2), one Al(4), and one H(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Al(1), one Al(3), and one H(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Al(3), one Al(4), and one H(5) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Mg(1), one Al(3), one Al(4), and one H(6) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Mg(1), one Al(1), one Al(2), and one H(7) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Al(1), one Al(2), and one H(8) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(3), and one H(9) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Al(2) and one Al(4) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to one Mg(1), one Al(4), and one H(11) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Al(1), one Al(3), and one H(12) atom. is represented by the CIF file [CIF]
data_MgAl4(HO)12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.551
_cell_length_b   7.410
_cell_length_c   7.308
_cell_angle_alpha   102.219
_cell_angle_beta   139.164
_cell_angle_gamma   92.692
_symmetry_Int_Tables_number   1
_cell_volume   247.201
_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  0.989  0.219  0.782  1.0
  Al  Al1  1  0.490  0.823  0.303  1.0
  Al  Al2  1  0.440  0.084  0.628  1.0
  Al  Al3  1  0.983  0.673  0.640  1.0
  Al  Al4  1  0.013  0.369  0.313  1.0
  H  H5  1  0.957  0.943  0.499  1.0
  H  H6  1  0.928  0.013  0.228  1.0
  H  H7  1  0.474  0.415  0.823  1.0
  H  H8  1  0.481  0.455  0.206  1.0
  H  H9  1  0.003  0.715  0.326  1.0
  H  H10  1  0.741  0.320  0.367  1.0
  H  H11  1  0.443  0.171  0.296  1.0
  H  H12  1  0.681  0.821  0.767  1.0
  H  H13  1  0.473  0.910  0.972  1.0
  H  H14  1  0.383  0.252  0.087  1.0
  H  H15  1  0.274  0.474  0.269  1.0
  H  H16  1  0.012  0.611  0.986  1.0
  O  O17  1  0.901  0.926  0.587  1.0
  O  O18  1  0.072  0.955  0.375  1.0
  O  O19  1  0.362  0.335  0.620  1.0
  O  O20  1  0.587  0.595  0.350  1.0
  O  O21  1  0.963  0.604  0.359  1.0
  O  O22  1  0.952  0.384  0.562  1.0
  O  O23  1  0.527  0.104  0.443  1.0
  O  O24  1  0.520  0.848  0.589  1.0
  O  O25  1  0.385  0.807  0.970  1.0
  O  O26  1  0.711  0.158  0.025  1.0
  O  O27  1  0.073  0.393  0.112  1.0
  O  O28  1  0.085  0.716  0.975  1.0
[/CIF]
.
The structure described by MgAl4(HO)12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one H(10), one O(1), one O(11), one O(6), and one O(7) atom to form MgHO4 trigonal bipyramids that share corners with two equivalent Al(3)O6 octahedra,  a cornercorner with one Al(2)O5 trigonal bipyramid, corners with two equivalent Al(4)O5 trigonal bipyramids, and  an edgeedge with one Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-52°. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(12), one O(4), one O(7), one O(8), and one O(9) atom to form AlO6 octahedra that share edges with two equivalent Al(3)O6 octahedra,  an edgeedge with one Mg(1)HO4 trigonal bipyramid, and  an edgeedge with one Al(2)O5 trigonal bipyramid. In the second Al site, Al(2) is bonded to one O(10), one O(2), one O(3), one O(7), and one O(8) atom to form AlO5 trigonal bipyramids that share  a cornercorner with one Mg(1)HO4 trigonal bipyramid, corners with two equivalent Al(4)O5 trigonal bipyramids, and  an edgeedge with one Al(1)O6 octahedra. In the third Al site, Al(3) is bonded to one O(1), one O(12), one O(4), one O(5), one O(6), and one O(9) atom to form AlO6 octahedra that share corners with two equivalent Mg(1)HO4 trigonal bipyramids, edges with two equivalent Al(1)O6 octahedra, and  an edgeedge with one Al(4)O5 trigonal bipyramid. In the fourth Al site, Al(4) is bonded to one O(10), one O(11), one O(3), one O(5), and one O(6) atom to form distorted AlO5 trigonal bipyramids that share corners with two equivalent Mg(1)HO4 trigonal bipyramids, corners with two equivalent Al(2)O5 trigonal bipyramids, and  an edgeedge with one Al(3)O6 octahedra. There are twelve inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(2) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(3) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(4) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(5) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(6) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(7) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(8) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(9) atom. In the tenth H site, H(10) is bonded in a single-bond geometry to one Mg(1) atom. In the eleventh H site, H(11) is bonded in a single-bond geometry to one O(11) atom. In the twelfth H site, H(12) is bonded in a single-bond geometry to one O(12) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Mg(1), one Al(1), one Al(3), and one H(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Al(2) and one H(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Al(2), one Al(4), and one H(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Al(1), one Al(3), and one H(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Al(3), one Al(4), and one H(5) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Mg(1), one Al(3), one Al(4), and one H(6) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Mg(1), one Al(1), one Al(2), and one H(7) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Al(1), one Al(2), and one H(8) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(3), and one H(9) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Al(2) and one Al(4) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to one Mg(1), one Al(4), and one H(11) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Al(1), one Al(3), and one H(12) atom. is represented by the CIF file [CIF]
data_MgAl4(HO)12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.551
_cell_length_b   7.410
_cell_length_c   7.308
_cell_angle_alpha   102.219
_cell_angle_beta   139.164
_cell_angle_gamma   92.692
_symmetry_Int_Tables_number   1
_cell_volume   247.201
_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  0.989  0.219  0.782  1.0
  Al  Al1  1  0.490  0.823  0.303  1.0
  Al  Al2  1  0.440  0.084  0.628  1.0
  Al  Al3  1  0.983  0.673  0.640  1.0
  Al  Al4  1  0.013  0.369  0.313  1.0
  H  H5  1  0.957  0.943  0.499  1.0
  H  H6  1  0.928  0.013  0.228  1.0
  H  H7  1  0.474  0.415  0.823  1.0
  H  H8  1  0.481  0.455  0.206  1.0
  H  H9  1  0.003  0.715  0.326  1.0
  H  H10  1  0.741  0.320  0.367  1.0
  H  H11  1  0.443  0.171  0.296  1.0
  H  H12  1  0.681  0.821  0.767  1.0
  H  H13  1  0.473  0.910  0.972  1.0
  H  H14  1  0.383  0.252  0.087  1.0
  H  H15  1  0.274  0.474  0.269  1.0
  H  H16  1  0.012  0.611  0.986  1.0
  O  O17  1  0.901  0.926  0.587  1.0
  O  O18  1  0.072  0.955  0.375  1.0
  O  O19  1  0.362  0.335  0.620  1.0
  O  O20  1  0.587  0.595  0.350  1.0
  O  O21  1  0.963  0.604  0.359  1.0
  O  O22  1  0.952  0.384  0.562  1.0
  O  O23  1  0.527  0.104  0.443  1.0
  O  O24  1  0.520  0.848  0.589  1.0
  O  O25  1  0.385  0.807  0.970  1.0
  O  O26  1  0.711  0.158  0.025  1.0
  O  O27  1  0.073  0.393  0.112  1.0
  O  O28  1  0.085  0.716  0.975  1.0
[/CIF]
.