The compound described by Mg(BH3)2 crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 7-coordinate geometry to one H(10), one H(16), one H(18), one H(2), one H(22), one H(4), and one H(5) atom. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one H(13), one H(15), one H(19), one H(20), one H(3), and one H(9) atom. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one H(1), one H(14), one H(23), one H(5), one H(6), and one H(7) atom. In the fourth Mg site, Mg(4) is bonded in a 6-coordinate geometry to one H(11), one H(12), one H(17), one H(21), one H(24), and one H(8) atom. There are eight inequivalent B sites. In the first B site, B(1) is bonded in a distorted trigonal non-coplanar geometry to one H(13), one H(2), and one H(9) atom. In the second B site, B(2) is bonded in a distorted trigonal non-coplanar geometry to one H(1), one H(10), and one H(14) atom. In the third B site, B(3) is bonded in a distorted trigonal non-coplanar geometry to one H(11), one H(16), and one H(4) atom. In the fourth B site, B(4) is bonded in a distorted trigonal non-coplanar geometry to one H(12), one H(15), and one H(3) atom. In the fifth B site, B(5) is bonded in a distorted trigonal non-coplanar geometry to one H(17), one H(21), and one H(6) atom. In the sixth B site, B(6) is bonded in a distorted trigonal non-coplanar geometry to one H(18), one H(22), and one H(5) atom. In the seventh B site, B(7) is bonded in a distorted trigonal non-coplanar geometry to one H(19), one H(24), and one H(8) atom. In the eighth B site, B(8) is bonded in a distorted trigonal non-coplanar geometry to one H(20), one H(23), and one H(7) atom. There are twenty-four inequivalent H sites. In the first H site, H(1) is bonded in an L-shaped geometry to one Mg(3) and one B(2) atom. In the second H site, H(2) is bonded in an L-shaped geometry to one Mg(1) and one B(1) atom. In the third H site, H(3) is bonded in a distorted L-shaped geometry to one Mg(2) and one B(4) atom. In the fourth H site, H(4) is bonded in an L-shaped geometry to one Mg(1) and one B(3) atom. In the fifth H site, H(5) is bonded in a 3-coordinate geometry to one Mg(1), one Mg(3), and one B(6) atom. In the sixth H site, H(6) is bonded in an L-shaped geometry to one Mg(3) and one B(5) atom. In the seventh H site, H(7) is bonded in an L-shaped geometry to one Mg(3) and one B(8) atom. In the eighth H site, H(8) is bonded in an L-shaped geometry to one Mg(4) and one B(7) atom. In the ninth H site, H(9) is bonded in an L-shaped geometry to one Mg(2) and one B(1) atom. In the tenth H site, H(10) is bonded in an L-shaped geometry to one Mg(1) and one B(2) atom. In the eleventh H site, H(11) is bonded in a distorted L-shaped geometry to one Mg(4) and one B(3) atom. In the twelfth H site, H(12) is bonded in an L-shaped geometry to one Mg(4) and one B(4) atom. In the thirteenth H site, H(13) is bonded in an L-shaped geometry to one Mg(2) and one B(1) atom. In the fourteenth H site, H(14) is bonded in an L-shaped geometry to one Mg(3) and one B(2) atom. In the fifteenth H site, H(15) is bonded in an L-shaped geometry to one Mg(2) and one B(4) atom. In the sixteenth H site, H(16) is bonded in an L-shaped geometry to one Mg(1) and one B(3) atom. In the seventeenth H site, H(17) is bonded in an L-shaped geometry to one Mg(4) and one B(5) atom. In the eighteenth H site, H(18) is bonded in an L-shaped geometry to one Mg(1) and one B(6) atom. In the nineteenth H site, H(19) is bonded in an L-shaped geometry to one Mg(2) and one B(7) atom. In the twentieth H site, H(20) is bonded in an L-shaped geometry to one Mg(2) and one B(8) atom. In the twenty-first H site, H(21) is bonded in an L-shaped geometry to one Mg(4) and one B(5) atom. In the twenty-second H site, H(22) is bonded in a distorted single-bond geometry to one Mg(1) and one B(6) atom. In the twenty-third H site, H(23) is bonded in an L-shaped geometry to one Mg(3) and one B(8) atom. In the twenty-fourth H site, H(24) is bonded in an L-shaped geometry to one Mg(4) and one B(7) atom. is represented by the CIF file [CIF]
data_Mg(BH3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.780
_cell_length_b   7.977
_cell_length_c   8.815
_cell_angle_alpha   92.172
_cell_angle_beta   93.771
_cell_angle_gamma   92.901
_symmetry_Int_Tables_number   1
_cell_volume   544.677
_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  0.350  0.130  0.017  1.0
  Mg  Mg1  1  0.843  0.814  0.872  1.0
  Mg  Mg2  1  0.820  0.326  0.139  1.0
  Mg  Mg3  1  0.675  0.281  0.643  1.0
  B  B4  1  0.089  0.963  0.006  1.0
  B  B5  1  0.056  0.178  0.052  1.0
  B  B6  1  0.473  0.131  0.771  1.0
  B  B7  1  0.665  0.020  0.777  1.0
  B  B8  1  0.683  0.290  0.373  1.0
  B  B9  1  0.555  0.198  0.215  1.0
  B  B10  1  0.800  0.530  0.781  1.0
  B  B11  1  0.773  0.556  0.979  1.0
  H  H12  1  0.930  0.212  0.970  1.0
  H  H13  1  0.229  0.901  0.040  1.0
  H  H14  1  0.642  0.883  0.708  1.0
  H  H15  1  0.482  0.255  0.862  1.0
  H  H16  1  0.634  0.135  0.110  1.0
  H  H17  1  0.804  0.395  0.356  1.0
  H  H18  1  0.909  0.543  0.059  1.0
  H  H19  1  0.655  0.521  0.712  1.0
  H  H20  1  0.071  0.935  0.865  1.0
  H  H21  1  0.163  0.292  0.026  1.0
  H  H22  1  0.421  0.191  0.650  1.0
  H  H23  1  0.800  0.084  0.730  1.0
  H  H24  1  0.988  0.876  0.074  1.0
  H  H25  1  0.034  0.198  0.190  1.0
  H  H26  1  0.702  0.003  0.914  1.0
  H  H27  1  0.353  0.034  0.797  1.0
  H  H28  1  0.753  0.180  0.448  1.0
  H  H29  1  0.469  0.309  0.159  1.0
  H  H30  1  0.881  0.636  0.710  1.0
  H  H31  1  0.715  0.687  0.030  1.0
  H  H32  1  0.585  0.373  0.446  1.0
  H  H33  1  0.461  0.083  0.254  1.0
  H  H34  1  0.659  0.453  0.007  1.0
  H  H35  1  0.881  0.403  0.758  1.0
[/CIF]
.
The compound described by Mg(BH3)2 crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 7-coordinate geometry to one H(10), one H(16), one H(18), one H(2), one H(22), one H(4), and one H(5) atom. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one H(13), one H(15), one H(19), one H(20), one H(3), and one H(9) atom. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one H(1), one H(14), one H(23), one H(5), one H(6), and one H(7) atom. In the fourth Mg site, Mg(4) is bonded in a 6-coordinate geometry to one H(11), one H(12), one H(17), one H(21), one H(24), and one H(8) atom. There are eight inequivalent B sites. In the first B site, B(1) is bonded in a distorted trigonal non-coplanar geometry to one H(13), one H(2), and one H(9) atom. In the second B site, B(2) is bonded in a distorted trigonal non-coplanar geometry to one H(1), one H(10), and one H(14) atom. In the third B site, B(3) is bonded in a distorted trigonal non-coplanar geometry to one H(11), one H(16), and one H(4) atom. In the fourth B site, B(4) is bonded in a distorted trigonal non-coplanar geometry to one H(12), one H(15), and one H(3) atom. In the fifth B site, B(5) is bonded in a distorted trigonal non-coplanar geometry to one H(17), one H(21), and one H(6) atom. In the sixth B site, B(6) is bonded in a distorted trigonal non-coplanar geometry to one H(18), one H(22), and one H(5) atom. In the seventh B site, B(7) is bonded in a distorted trigonal non-coplanar geometry to one H(19), one H(24), and one H(8) atom. In the eighth B site, B(8) is bonded in a distorted trigonal non-coplanar geometry to one H(20), one H(23), and one H(7) atom. There are twenty-four inequivalent H sites. In the first H site, H(1) is bonded in an L-shaped geometry to one Mg(3) and one B(2) atom. In the second H site, H(2) is bonded in an L-shaped geometry to one Mg(1) and one B(1) atom. In the third H site, H(3) is bonded in a distorted L-shaped geometry to one Mg(2) and one B(4) atom. In the fourth H site, H(4) is bonded in an L-shaped geometry to one Mg(1) and one B(3) atom. In the fifth H site, H(5) is bonded in a 3-coordinate geometry to one Mg(1), one Mg(3), and one B(6) atom. In the sixth H site, H(6) is bonded in an L-shaped geometry to one Mg(3) and one B(5) atom. In the seventh H site, H(7) is bonded in an L-shaped geometry to one Mg(3) and one B(8) atom. In the eighth H site, H(8) is bonded in an L-shaped geometry to one Mg(4) and one B(7) atom. In the ninth H site, H(9) is bonded in an L-shaped geometry to one Mg(2) and one B(1) atom. In the tenth H site, H(10) is bonded in an L-shaped geometry to one Mg(1) and one B(2) atom. In the eleventh H site, H(11) is bonded in a distorted L-shaped geometry to one Mg(4) and one B(3) atom. In the twelfth H site, H(12) is bonded in an L-shaped geometry to one Mg(4) and one B(4) atom. In the thirteenth H site, H(13) is bonded in an L-shaped geometry to one Mg(2) and one B(1) atom. In the fourteenth H site, H(14) is bonded in an L-shaped geometry to one Mg(3) and one B(2) atom. In the fifteenth H site, H(15) is bonded in an L-shaped geometry to one Mg(2) and one B(4) atom. In the sixteenth H site, H(16) is bonded in an L-shaped geometry to one Mg(1) and one B(3) atom. In the seventeenth H site, H(17) is bonded in an L-shaped geometry to one Mg(4) and one B(5) atom. In the eighteenth H site, H(18) is bonded in an L-shaped geometry to one Mg(1) and one B(6) atom. In the nineteenth H site, H(19) is bonded in an L-shaped geometry to one Mg(2) and one B(7) atom. In the twentieth H site, H(20) is bonded in an L-shaped geometry to one Mg(2) and one B(8) atom. In the twenty-first H site, H(21) is bonded in an L-shaped geometry to one Mg(4) and one B(5) atom. In the twenty-second H site, H(22) is bonded in a distorted single-bond geometry to one Mg(1) and one B(6) atom. In the twenty-third H site, H(23) is bonded in an L-shaped geometry to one Mg(3) and one B(8) atom. In the twenty-fourth H site, H(24) is bonded in an L-shaped geometry to one Mg(4) and one B(7) atom. is represented by the CIF file [CIF]
data_Mg(BH3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.780
_cell_length_b   7.977
_cell_length_c   8.815
_cell_angle_alpha   92.172
_cell_angle_beta   93.771
_cell_angle_gamma   92.901
_symmetry_Int_Tables_number   1
_cell_volume   544.677
_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  0.350  0.130  0.017  1.0
  Mg  Mg1  1  0.843  0.814  0.872  1.0
  Mg  Mg2  1  0.820  0.326  0.139  1.0
  Mg  Mg3  1  0.675  0.281  0.643  1.0
  B  B4  1  0.089  0.963  0.006  1.0
  B  B5  1  0.056  0.178  0.052  1.0
  B  B6  1  0.473  0.131  0.771  1.0
  B  B7  1  0.665  0.020  0.777  1.0
  B  B8  1  0.683  0.290  0.373  1.0
  B  B9  1  0.555  0.198  0.215  1.0
  B  B10  1  0.800  0.530  0.781  1.0
  B  B11  1  0.773  0.556  0.979  1.0
  H  H12  1  0.930  0.212  0.970  1.0
  H  H13  1  0.229  0.901  0.040  1.0
  H  H14  1  0.642  0.883  0.708  1.0
  H  H15  1  0.482  0.255  0.862  1.0
  H  H16  1  0.634  0.135  0.110  1.0
  H  H17  1  0.804  0.395  0.356  1.0
  H  H18  1  0.909  0.543  0.059  1.0
  H  H19  1  0.655  0.521  0.712  1.0
  H  H20  1  0.071  0.935  0.865  1.0
  H  H21  1  0.163  0.292  0.026  1.0
  H  H22  1  0.421  0.191  0.650  1.0
  H  H23  1  0.800  0.084  0.730  1.0
  H  H24  1  0.988  0.876  0.074  1.0
  H  H25  1  0.034  0.198  0.190  1.0
  H  H26  1  0.702  0.003  0.914  1.0
  H  H27  1  0.353  0.034  0.797  1.0
  H  H28  1  0.753  0.180  0.448  1.0
  H  H29  1  0.469  0.309  0.159  1.0
  H  H30  1  0.881  0.636  0.710  1.0
  H  H31  1  0.715  0.687  0.030  1.0
  H  H32  1  0.585  0.373  0.446  1.0
  H  H33  1  0.461  0.083  0.254  1.0
  H  H34  1  0.659  0.453  0.007  1.0
  H  H35  1  0.881  0.403  0.758  1.0
[/CIF]
.