The material structure described by Ba2AlH7 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 11-coordinate geometry to one H(3), one H(4), one H(5), one H(7), two equivalent H(1), two equivalent H(2), and three equivalent H(6) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one H(1), one H(2), one H(4), two equivalent H(3), two equivalent H(5), and three equivalent H(7) atoms. Al(1) is bonded in an octahedral geometry to one H(1), one H(2), one H(3), one H(4), one H(5), and one H(6) atom. There are seven inequivalent H sites. In the first H site, H(3) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one Al(1) atom. In the second H site, H(4) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one Al(1) atom. In the third H site, H(5) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one Al(1) atom. In the fourth H site, H(6) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one Al(1) atom. In the fifth H site, H(7) is bonded to one Ba(1) and three equivalent Ba(2) atoms to form a mixture of edge and corner-sharing HBa4 tetrahedra. In the sixth H site, H(1) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one Al(1) atom. In the seventh H site, H(2) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one Al(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba2AlH7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.801
_cell_length_b   8.801
_cell_length_c   8.561
_cell_angle_alpha   70.061
_cell_angle_beta   70.061
_cell_angle_gamma   71.597
_symmetry_Int_Tables_number   1
_cell_volume   570.872
_cell_formula_units_Z   4
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
  Ba  Ba0  1  0.259  0.929  0.482  1.0
  Ba  Ba1  1  0.071  0.741  0.018  1.0
  Ba  Ba2  1  0.741  0.071  0.518  1.0
  Ba  Ba3  1  0.929  0.259  0.982  1.0
  Ba  Ba4  1  0.281  0.432  0.479  1.0
  Ba  Ba5  1  0.568  0.719  0.021  1.0
  Ba  Ba6  1  0.719  0.568  0.521  1.0
  Ba  Ba7  1  0.432  0.281  0.979  1.0
  Al  Al8  1  0.319  0.032  0.801  1.0
  Al  Al9  1  0.968  0.681  0.699  1.0
  Al  Al10  1  0.681  0.968  0.199  1.0
  Al  Al11  1  0.032  0.319  0.301  1.0
  H  H12  1  0.392  0.105  0.581  1.0
  H  H13  1  0.895  0.608  0.919  1.0
  H  H14  1  0.608  0.895  0.419  1.0
  H  H15  1  0.105  0.392  0.081  1.0
  H  H16  1  0.379  0.824  0.780  1.0
  H  H17  1  0.176  0.621  0.720  1.0
  H  H18  1  0.621  0.176  0.220  1.0
  H  H19  1  0.824  0.379  0.280  1.0
  H  H20  1  0.510  0.019  0.827  1.0
  H  H21  1  0.981  0.490  0.673  1.0
  H  H22  1  0.490  0.981  0.173  1.0
  H  H23  1  0.019  0.510  0.327  1.0
  H  H24  1  0.254  0.947  0.023  1.0
  H  H25  1  0.053  0.746  0.477  1.0
  H  H26  1  0.746  0.053  0.977  1.0
  H  H27  1  0.947  0.254  0.523  1.0
  H  H28  1  0.247  0.235  0.818  1.0
  H  H29  1  0.765  0.753  0.682  1.0
  H  H30  1  0.753  0.765  0.182  1.0
  H  H31  1  0.235  0.247  0.318  1.0
  H  H32  1  0.126  0.039  0.785  1.0
  H  H33  1  0.961  0.874  0.715  1.0
  H  H34  1  0.874  0.961  0.215  1.0
  H  H35  1  0.039  0.126  0.285  1.0
  H  H36  1  0.339  0.545  0.126  1.0
  H  H37  1  0.455  0.661  0.374  1.0
  H  H38  1  0.661  0.455  0.874  1.0
  H  H39  1  0.545  0.339  0.626  1.0
[/CIF]
.
The material structure described by Ba2AlH7 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 11-coordinate geometry to one H(3), one H(4), one H(5), one H(7), two equivalent H(1), two equivalent H(2), and three equivalent H(6) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one H(1), one H(2), one H(4), two equivalent H(3), two equivalent H(5), and three equivalent H(7) atoms. Al(1) is bonded in an octahedral geometry to one H(1), one H(2), one H(3), one H(4), one H(5), and one H(6) atom. There are seven inequivalent H sites. In the first H site, H(3) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one Al(1) atom. In the second H site, H(4) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one Al(1) atom. In the third H site, H(5) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one Al(1) atom. In the fourth H site, H(6) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one Al(1) atom. In the fifth H site, H(7) is bonded to one Ba(1) and three equivalent Ba(2) atoms to form a mixture of edge and corner-sharing HBa4 tetrahedra. In the sixth H site, H(1) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one Al(1) atom. In the seventh H site, H(2) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one Al(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba2AlH7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.801
_cell_length_b   8.801
_cell_length_c   8.561
_cell_angle_alpha   70.061
_cell_angle_beta   70.061
_cell_angle_gamma   71.597
_symmetry_Int_Tables_number   1
_cell_volume   570.872
_cell_formula_units_Z   4
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
  Ba  Ba0  1  0.259  0.929  0.482  1.0
  Ba  Ba1  1  0.071  0.741  0.018  1.0
  Ba  Ba2  1  0.741  0.071  0.518  1.0
  Ba  Ba3  1  0.929  0.259  0.982  1.0
  Ba  Ba4  1  0.281  0.432  0.479  1.0
  Ba  Ba5  1  0.568  0.719  0.021  1.0
  Ba  Ba6  1  0.719  0.568  0.521  1.0
  Ba  Ba7  1  0.432  0.281  0.979  1.0
  Al  Al8  1  0.319  0.032  0.801  1.0
  Al  Al9  1  0.968  0.681  0.699  1.0
  Al  Al10  1  0.681  0.968  0.199  1.0
  Al  Al11  1  0.032  0.319  0.301  1.0
  H  H12  1  0.392  0.105  0.581  1.0
  H  H13  1  0.895  0.608  0.919  1.0
  H  H14  1  0.608  0.895  0.419  1.0
  H  H15  1  0.105  0.392  0.081  1.0
  H  H16  1  0.379  0.824  0.780  1.0
  H  H17  1  0.176  0.621  0.720  1.0
  H  H18  1  0.621  0.176  0.220  1.0
  H  H19  1  0.824  0.379  0.280  1.0
  H  H20  1  0.510  0.019  0.827  1.0
  H  H21  1  0.981  0.490  0.673  1.0
  H  H22  1  0.490  0.981  0.173  1.0
  H  H23  1  0.019  0.510  0.327  1.0
  H  H24  1  0.254  0.947  0.023  1.0
  H  H25  1  0.053  0.746  0.477  1.0
  H  H26  1  0.746  0.053  0.977  1.0
  H  H27  1  0.947  0.254  0.523  1.0
  H  H28  1  0.247  0.235  0.818  1.0
  H  H29  1  0.765  0.753  0.682  1.0
  H  H30  1  0.753  0.765  0.182  1.0
  H  H31  1  0.235  0.247  0.318  1.0
  H  H32  1  0.126  0.039  0.785  1.0
  H  H33  1  0.961  0.874  0.715  1.0
  H  H34  1  0.874  0.961  0.215  1.0
  H  H35  1  0.039  0.126  0.285  1.0
  H  H36  1  0.339  0.545  0.126  1.0
  H  H37  1  0.455  0.661  0.374  1.0
  H  H38  1  0.661  0.455  0.874  1.0
  H  H39  1  0.545  0.339  0.626  1.0
[/CIF]
.