The compound described by Mg(BH4)2 crystallizes in the tetragonal I-4m2 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to four equivalent H(1) and four equivalent H(3) atoms. In the second Mg site, Mg(2) is bonded in a body-centered cubic geometry to eight equivalent H(2) atoms. B(1) is bonded in a tetrahedral geometry to one H(1), one H(3), and two equivalent H(2) atoms. There are three inequivalent H sites. In the first H site, H(1) is bonded in an L-shaped geometry to one Mg(1) and one B(1) atom. In the second H site, H(2) is bonded in an L-shaped geometry to one Mg(2) and one B(1) atom. In the third H site, H(3) is bonded in an L-shaped geometry to one Mg(1) and one B(1) atom. is represented by the CIF card [CIF]
data_Mg(BH4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.344
_cell_length_b   7.344
_cell_length_c   7.344
_cell_angle_alpha   110.839
_cell_angle_beta   110.839
_cell_angle_gamma   106.769
_symmetry_Int_Tables_number   1
_cell_volume   304.391
_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
  Mg  Mg0  1  0.750  0.250  0.500  1.0
  Mg  Mg1  1  0.000  0.000  0.000  1.0
  B  B2  1  0.392  0.169  0.224  1.0
  B  B3  1  0.945  0.169  0.776  1.0
  B  B4  1  0.831  0.608  0.776  1.0
  B  B5  1  0.831  0.055  0.224  1.0
  H  H6  1  0.050  0.306  0.744  1.0
  H  H7  1  0.694  0.438  0.744  1.0
  H  H8  1  0.694  0.950  0.256  1.0
  H  H9  1  0.562  0.306  0.256  1.0
  H  H10  1  0.997  0.271  0.976  1.0
  H  H11  1  0.295  0.022  0.024  1.0
  H  H12  1  0.729  0.003  0.024  1.0
  H  H13  1  0.978  0.705  0.976  1.0
  H  H14  1  0.295  0.271  0.273  1.0
  H  H15  1  0.997  0.022  0.727  1.0
  H  H16  1  0.729  0.705  0.727  1.0
  H  H17  1  0.978  0.003  0.273  1.0
  H  H18  1  0.742  0.081  0.662  1.0
  H  H19  1  0.419  0.081  0.338  1.0
  H  H20  1  0.919  0.258  0.338  1.0
  H  H21  1  0.919  0.581  0.662  1.0
[/CIF]
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The compound described by Mg(BH4)2 crystallizes in the tetragonal I-4m2 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to four equivalent H(1) and four equivalent H(3) atoms. In the second Mg site, Mg(2) is bonded in a body-centered cubic geometry to eight equivalent H(2) atoms. B(1) is bonded in a tetrahedral geometry to one H(1), one H(3), and two equivalent H(2) atoms. There are three inequivalent H sites. In the first H site, H(1) is bonded in an L-shaped geometry to one Mg(1) and one B(1) atom. In the second H site, H(2) is bonded in an L-shaped geometry to one Mg(2) and one B(1) atom. In the third H site, H(3) is bonded in an L-shaped geometry to one Mg(1) and one B(1) atom. is represented by the CIF card [CIF]
data_Mg(BH4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.344
_cell_length_b   7.344
_cell_length_c   7.344
_cell_angle_alpha   110.839
_cell_angle_beta   110.839
_cell_angle_gamma   106.769
_symmetry_Int_Tables_number   1
_cell_volume   304.391
_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
  Mg  Mg0  1  0.750  0.250  0.500  1.0
  Mg  Mg1  1  0.000  0.000  0.000  1.0
  B  B2  1  0.392  0.169  0.224  1.0
  B  B3  1  0.945  0.169  0.776  1.0
  B  B4  1  0.831  0.608  0.776  1.0
  B  B5  1  0.831  0.055  0.224  1.0
  H  H6  1  0.050  0.306  0.744  1.0
  H  H7  1  0.694  0.438  0.744  1.0
  H  H8  1  0.694  0.950  0.256  1.0
  H  H9  1  0.562  0.306  0.256  1.0
  H  H10  1  0.997  0.271  0.976  1.0
  H  H11  1  0.295  0.022  0.024  1.0
  H  H12  1  0.729  0.003  0.024  1.0
  H  H13  1  0.978  0.705  0.976  1.0
  H  H14  1  0.295  0.271  0.273  1.0
  H  H15  1  0.997  0.022  0.727  1.0
  H  H16  1  0.729  0.705  0.727  1.0
  H  H17  1  0.978  0.003  0.273  1.0
  H  H18  1  0.742  0.081  0.662  1.0
  H  H19  1  0.419  0.081  0.338  1.0
  H  H20  1  0.919  0.258  0.338  1.0
  H  H21  1  0.919  0.581  0.662  1.0
[/CIF]
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