The compound described by Mg(BH4)2 crystallizes in the cubic Fd-3m space group. The structure consists of a Mg(BH4)2 framework. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to twelve equivalent H(2) atoms to form distorted MgH12 cuboctahedra that share faces with four equivalent B(1)H4 tetrahedra. In the second Mg site, Mg(2) is bonded to four equivalent H(1) atoms to form MgH4 tetrahedra that share corners with four equivalent B(1)H4 tetrahedra. B(1) is bonded to one H(1) and three equivalent H(2) atoms to form BH4 tetrahedra that share  a cornercorner with one Mg(2)H4 tetrahedra and  a faceface with one Mg(1)H12 cuboctahedra. There are two inequivalent H sites. In the first H site, H(1) is bonded in a linear geometry to one Mg(2) and one B(1) atom. In the second H site, H(2) is bonded in a single-bond 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   8.778
_cell_length_b   8.778
_cell_length_c   8.778
_cell_angle_alpha   60.000
_cell_angle_beta   60.000
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   478.293
_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
  Mg  Mg0  1  0.250  0.250  0.250  1.0
  Mg  Mg1  1  0.000  0.000  0.000  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.750  0.750  0.750  1.0
  B  B4  1  0.924  0.359  0.359  1.0
  B  B5  1  0.359  0.924  0.359  1.0
  B  B6  1  0.359  0.359  0.924  1.0
  B  B7  1  0.359  0.359  0.359  1.0
  B  B8  1  0.326  0.891  0.891  1.0
  B  B9  1  0.891  0.326  0.891  1.0
  B  B10  1  0.891  0.891  0.326  1.0
  B  B11  1  0.891  0.891  0.891  1.0
  H  H12  1  0.751  0.416  0.416  1.0
  H  H13  1  0.416  0.751  0.416  1.0
  H  H14  1  0.416  0.416  0.751  1.0
  H  H15  1  0.416  0.416  0.416  1.0
  H  H16  1  0.499  0.834  0.834  1.0
  H  H17  1  0.834  0.499  0.834  1.0
  H  H18  1  0.834  0.834  0.499  1.0
  H  H19  1  0.834  0.834  0.834  1.0
  H  H20  1  0.495  0.266  0.266  1.0
  H  H21  1  0.266  0.495  0.974  1.0
  H  H22  1  0.266  0.974  0.495  1.0
  H  H23  1  0.974  0.266  0.266  1.0
  H  H24  1  0.266  0.266  0.495  1.0
  H  H25  1  0.495  0.974  0.266  1.0
  H  H26  1  0.974  0.495  0.266  1.0
  H  H27  1  0.266  0.266  0.974  1.0
  H  H28  1  0.266  0.495  0.266  1.0
  H  H29  1  0.974  0.266  0.495  1.0
  H  H30  1  0.495  0.266  0.974  1.0
  H  H31  1  0.266  0.974  0.266  1.0
  H  H32  1  0.755  0.984  0.984  1.0
  H  H33  1  0.984  0.755  0.276  1.0
  H  H34  1  0.984  0.276  0.755  1.0
  H  H35  1  0.276  0.984  0.984  1.0
  H  H36  1  0.984  0.984  0.755  1.0
  H  H37  1  0.755  0.276  0.984  1.0
  H  H38  1  0.276  0.755  0.984  1.0
  H  H39  1  0.984  0.984  0.276  1.0
  H  H40  1  0.984  0.755  0.984  1.0
  H  H41  1  0.276  0.984  0.755  1.0
  H  H42  1  0.755  0.984  0.276  1.0
  H  H43  1  0.984  0.276  0.984  1.0
[/CIF]
.
The compound described by Mg(BH4)2 crystallizes in the cubic Fd-3m space group. The structure consists of a Mg(BH4)2 framework. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to twelve equivalent H(2) atoms to form distorted MgH12 cuboctahedra that share faces with four equivalent B(1)H4 tetrahedra. In the second Mg site, Mg(2) is bonded to four equivalent H(1) atoms to form MgH4 tetrahedra that share corners with four equivalent B(1)H4 tetrahedra. B(1) is bonded to one H(1) and three equivalent H(2) atoms to form BH4 tetrahedra that share  a cornercorner with one Mg(2)H4 tetrahedra and  a faceface with one Mg(1)H12 cuboctahedra. There are two inequivalent H sites. In the first H site, H(1) is bonded in a linear geometry to one Mg(2) and one B(1) atom. In the second H site, H(2) is bonded in a single-bond 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   8.778
_cell_length_b   8.778
_cell_length_c   8.778
_cell_angle_alpha   60.000
_cell_angle_beta   60.000
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   478.293
_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
  Mg  Mg0  1  0.250  0.250  0.250  1.0
  Mg  Mg1  1  0.000  0.000  0.000  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.750  0.750  0.750  1.0
  B  B4  1  0.924  0.359  0.359  1.0
  B  B5  1  0.359  0.924  0.359  1.0
  B  B6  1  0.359  0.359  0.924  1.0
  B  B7  1  0.359  0.359  0.359  1.0
  B  B8  1  0.326  0.891  0.891  1.0
  B  B9  1  0.891  0.326  0.891  1.0
  B  B10  1  0.891  0.891  0.326  1.0
  B  B11  1  0.891  0.891  0.891  1.0
  H  H12  1  0.751  0.416  0.416  1.0
  H  H13  1  0.416  0.751  0.416  1.0
  H  H14  1  0.416  0.416  0.751  1.0
  H  H15  1  0.416  0.416  0.416  1.0
  H  H16  1  0.499  0.834  0.834  1.0
  H  H17  1  0.834  0.499  0.834  1.0
  H  H18  1  0.834  0.834  0.499  1.0
  H  H19  1  0.834  0.834  0.834  1.0
  H  H20  1  0.495  0.266  0.266  1.0
  H  H21  1  0.266  0.495  0.974  1.0
  H  H22  1  0.266  0.974  0.495  1.0
  H  H23  1  0.974  0.266  0.266  1.0
  H  H24  1  0.266  0.266  0.495  1.0
  H  H25  1  0.495  0.974  0.266  1.0
  H  H26  1  0.974  0.495  0.266  1.0
  H  H27  1  0.266  0.266  0.974  1.0
  H  H28  1  0.266  0.495  0.266  1.0
  H  H29  1  0.974  0.266  0.495  1.0
  H  H30  1  0.495  0.266  0.974  1.0
  H  H31  1  0.266  0.974  0.266  1.0
  H  H32  1  0.755  0.984  0.984  1.0
  H  H33  1  0.984  0.755  0.276  1.0
  H  H34  1  0.984  0.276  0.755  1.0
  H  H35  1  0.276  0.984  0.984  1.0
  H  H36  1  0.984  0.984  0.755  1.0
  H  H37  1  0.755  0.276  0.984  1.0
  H  H38  1  0.276  0.755  0.984  1.0
  H  H39  1  0.984  0.984  0.276  1.0
  H  H40  1  0.984  0.755  0.984  1.0
  H  H41  1  0.276  0.984  0.755  1.0
  H  H42  1  0.755  0.984  0.276  1.0
  H  H43  1  0.984  0.276  0.984  1.0
[/CIF]
.