The material structure described by CaAlH5 crystallizes in the orthorhombic P2_12_12_1 space group. Ca(1) is bonded in a 11-coordinate geometry to one H(3), two equivalent H(1), two equivalent H(2), three equivalent H(4), and three equivalent H(5) atoms. Al(1) is bonded to one H(1), one H(2), one H(4), one H(5), and two equivalent H(3) atoms to form corner-sharing AlH6 octahedra. The corner-sharing octahedral tilt angles are 43°. There are five inequivalent H sites. In the first H site, H(1) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Al(1) atom. In the second H site, H(2) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Al(1) atom. In the third H site, H(3) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Al(1) atoms. In the fourth H site, H(4) is bonded in a 1-coordinate geometry to three equivalent Ca(1) and one Al(1) atom. In the fifth H site, H(5) is bonded in a distorted single-bond geometry to three equivalent Ca(1) and one Al(1) atom. is represented by the CIF file [CIF]
data_CaAlH5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.417
_cell_length_b   4.941
_cell_length_c   12.169
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   265.603
_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
  Ca  Ca0  1  0.718  0.352  0.159  1.0
  Ca  Ca1  1  0.218  0.148  0.841  1.0
  Ca  Ca2  1  0.282  0.852  0.341  1.0
  Ca  Ca3  1  0.782  0.648  0.659  1.0
  Al  Al4  1  0.191  0.130  0.587  1.0
  Al  Al5  1  0.309  0.870  0.087  1.0
  Al  Al6  1  0.809  0.630  0.913  1.0
  Al  Al7  1  0.691  0.370  0.413  1.0
  H  H8  1  0.965  0.374  0.986  1.0
  H  H9  1  0.357  0.912  0.678  1.0
  H  H10  1  0.011  0.873  0.993  1.0
  H  H11  1  0.684  0.904  0.840  1.0
  H  H12  1  0.386  0.370  0.322  1.0
  H  H13  1  0.816  0.096  0.340  1.0
  H  H14  1  0.511  0.627  0.007  1.0
  H  H15  1  0.316  0.404  0.660  1.0
  H  H16  1  0.857  0.588  0.322  1.0
  H  H17  1  0.535  0.626  0.486  1.0
  H  H18  1  0.989  0.373  0.507  1.0
  H  H19  1  0.035  0.874  0.514  1.0
  H  H20  1  0.614  0.870  0.178  1.0
  H  H21  1  0.886  0.130  0.678  1.0
  H  H22  1  0.114  0.630  0.822  1.0
  H  H23  1  0.143  0.088  0.178  1.0
  H  H24  1  0.465  0.126  0.014  1.0
  H  H25  1  0.643  0.412  0.822  1.0
  H  H26  1  0.489  0.127  0.493  1.0
  H  H27  1  0.184  0.596  0.160  1.0
[/CIF]
.
The material structure described by CaAlH5 crystallizes in the orthorhombic P2_12_12_1 space group. Ca(1) is bonded in a 11-coordinate geometry to one H(3), two equivalent H(1), two equivalent H(2), three equivalent H(4), and three equivalent H(5) atoms. Al(1) is bonded to one H(1), one H(2), one H(4), one H(5), and two equivalent H(3) atoms to form corner-sharing AlH6 octahedra. The corner-sharing octahedral tilt angles are 43°. There are five inequivalent H sites. In the first H site, H(1) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Al(1) atom. In the second H site, H(2) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Al(1) atom. In the third H site, H(3) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Al(1) atoms. In the fourth H site, H(4) is bonded in a 1-coordinate geometry to three equivalent Ca(1) and one Al(1) atom. In the fifth H site, H(5) is bonded in a distorted single-bond geometry to three equivalent Ca(1) and one Al(1) atom. is represented by the CIF file [CIF]
data_CaAlH5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.417
_cell_length_b   4.941
_cell_length_c   12.169
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   265.603
_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
  Ca  Ca0  1  0.718  0.352  0.159  1.0
  Ca  Ca1  1  0.218  0.148  0.841  1.0
  Ca  Ca2  1  0.282  0.852  0.341  1.0
  Ca  Ca3  1  0.782  0.648  0.659  1.0
  Al  Al4  1  0.191  0.130  0.587  1.0
  Al  Al5  1  0.309  0.870  0.087  1.0
  Al  Al6  1  0.809  0.630  0.913  1.0
  Al  Al7  1  0.691  0.370  0.413  1.0
  H  H8  1  0.965  0.374  0.986  1.0
  H  H9  1  0.357  0.912  0.678  1.0
  H  H10  1  0.011  0.873  0.993  1.0
  H  H11  1  0.684  0.904  0.840  1.0
  H  H12  1  0.386  0.370  0.322  1.0
  H  H13  1  0.816  0.096  0.340  1.0
  H  H14  1  0.511  0.627  0.007  1.0
  H  H15  1  0.316  0.404  0.660  1.0
  H  H16  1  0.857  0.588  0.322  1.0
  H  H17  1  0.535  0.626  0.486  1.0
  H  H18  1  0.989  0.373  0.507  1.0
  H  H19  1  0.035  0.874  0.514  1.0
  H  H20  1  0.614  0.870  0.178  1.0
  H  H21  1  0.886  0.130  0.678  1.0
  H  H22  1  0.114  0.630  0.822  1.0
  H  H23  1  0.143  0.088  0.178  1.0
  H  H24  1  0.465  0.126  0.014  1.0
  H  H25  1  0.643  0.412  0.822  1.0
  H  H26  1  0.489  0.127  0.493  1.0
  H  H27  1  0.184  0.596  0.160  1.0
[/CIF]
.