The structure described by RbAlH4 crystallizes in the orthorhombic Cmc2_1 space group. Rb(1) is bonded in a 8-coordinate geometry to one H(2), two equivalent H(3), two equivalent H(4), and three equivalent H(1) atoms. Al(1) is bonded to one H(1), one H(3), one H(4), and two equivalent H(2) atoms to form corner-sharing AlH5 trigonal bipyramids. There are four inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Al(1) atom. In the second H site, H(2) is bonded in a linear geometry to one Rb(1) and two equivalent Al(1) atoms. In the third H site, H(3) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Al(1) atom. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Al(1) atom. is represented by the CIF card [CIF]
data_RbAlH4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.738
_cell_length_b   7.738
_cell_length_c   6.510
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   151.473
_symmetry_Int_Tables_number   1
_cell_volume   186.170
_cell_formula_units_Z   2
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
  Rb  Rb0  1  0.620  0.380  0.166  1.0
  Rb  Rb1  1  0.380  0.620  0.666  1.0
  Al  Al2  1  0.884  0.116  0.144  1.0
  Al  Al3  1  0.116  0.884  0.644  1.0
  H  H4  1  0.808  0.192  0.965  1.0
  H  H5  1  0.192  0.808  0.465  1.0
  H  H6  1  0.391  0.609  0.153  1.0
  H  H7  1  0.609  0.391  0.653  1.0
  H  H8  1  0.015  0.985  0.546  1.0
  H  H9  1  0.985  0.015  0.046  1.0
  H  H10  1  0.848  0.152  0.379  1.0
  H  H11  1  0.152  0.848  0.879  1.0
[/CIF]
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The structure described by RbAlH4 crystallizes in the orthorhombic Cmc2_1 space group. Rb(1) is bonded in a 8-coordinate geometry to one H(2), two equivalent H(3), two equivalent H(4), and three equivalent H(1) atoms. Al(1) is bonded to one H(1), one H(3), one H(4), and two equivalent H(2) atoms to form corner-sharing AlH5 trigonal bipyramids. There are four inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Al(1) atom. In the second H site, H(2) is bonded in a linear geometry to one Rb(1) and two equivalent Al(1) atoms. In the third H site, H(3) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Al(1) atom. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Al(1) atom. is represented by the CIF card [CIF]
data_RbAlH4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.738
_cell_length_b   7.738
_cell_length_c   6.510
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   151.473
_symmetry_Int_Tables_number   1
_cell_volume   186.170
_cell_formula_units_Z   2
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
  Rb  Rb0  1  0.620  0.380  0.166  1.0
  Rb  Rb1  1  0.380  0.620  0.666  1.0
  Al  Al2  1  0.884  0.116  0.144  1.0
  Al  Al3  1  0.116  0.884  0.644  1.0
  H  H4  1  0.808  0.192  0.965  1.0
  H  H5  1  0.192  0.808  0.465  1.0
  H  H6  1  0.391  0.609  0.153  1.0
  H  H7  1  0.609  0.391  0.653  1.0
  H  H8  1  0.015  0.985  0.546  1.0
  H  H9  1  0.985  0.015  0.046  1.0
  H  H10  1  0.848  0.152  0.379  1.0
  H  H11  1  0.152  0.848  0.879  1.0
[/CIF]
.