The crystal structure described by B12C2Mg crystallizes in the orthorhombic Imma space group. Mg(1) is bonded in a 2-coordinate geometry to eight equivalent B(3) and two equivalent C(1) atoms. There are four inequivalent B sites. In the first B site, B(1) is bonded in a distorted single-bond geometry to one B(4), two equivalent B(3), and one C(1) atom. In the second B site, B(2) is bonded in a distorted single-bond geometry to one B(4), two equivalent B(3), and one C(1) atom. In the third B site, B(3) is bonded in a 8-coordinate geometry to two equivalent Mg(1), one B(2), one B(4), two equivalent B(1), and two equivalent B(3) atoms. In the fourth B site, B(4) is bonded in a 6-coordinate geometry to one B(2), one B(4), two equivalent B(1), and two equivalent B(3) atoms. C(1) is bonded in a 5-coordinate geometry to one Mg(1), one B(2), two equivalent B(1), and one C(1) atom. is represented by the CIF file [CIF]
data_Mg(B6C)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.897
_cell_length_b   6.897
_cell_length_c   6.897
_cell_angle_alpha   132.058
_cell_angle_beta   109.938
_cell_angle_gamma   89.376
_symmetry_Int_Tables_number   1
_cell_volume   217.595
_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  0.387  0.750  0.637  1.0
  Mg  Mg1  1  0.613  0.250  0.363  1.0
  B  B2  1  0.637  0.845  0.312  1.0
  B  B3  1  0.225  0.406  0.819  1.0
  B  B4  1  0.775  0.774  0.678  1.0
  B  B5  1  0.033  0.825  0.688  1.0
  B  B6  1  0.363  0.675  0.208  1.0
  B  B7  1  0.967  0.175  0.312  1.0
  B  B8  1  0.404  0.403  0.678  1.0
  B  B9  1  0.775  0.594  0.181  1.0
  B  B10  1  0.363  0.155  0.688  1.0
  B  B11  1  0.354  0.333  0.021  1.0
  B  B12  1  0.596  0.597  0.322  1.0
  B  B13  1  0.812  0.833  0.979  1.0
  B  B14  1  0.967  0.655  0.792  1.0
  B  B15  1  0.088  0.906  0.181  1.0
  B  B16  1  0.596  0.274  0.999  1.0
  B  B17  1  0.637  0.325  0.792  1.0
  B  B18  1  0.404  0.726  0.001  1.0
  B  B19  1  0.775  0.097  0.001  1.0
  B  B20  1  0.225  0.903  0.999  1.0
  B  B21  1  0.912  0.094  0.819  1.0
  B  B22  1  0.646  0.667  0.979  1.0
  B  B23  1  0.225  0.226  0.322  1.0
  B  B24  1  0.188  0.167  0.021  1.0
  B  B25  1  0.033  0.345  0.208  1.0
  C  C26  1  0.967  0.338  0.629  1.0
  C  C27  1  0.209  0.838  0.371  1.0
  C  C28  1  0.791  0.162  0.629  1.0
  C  C29  1  0.033  0.662  0.371  1.0
[/CIF]
.
The crystal structure described by B12C2Mg crystallizes in the orthorhombic Imma space group. Mg(1) is bonded in a 2-coordinate geometry to eight equivalent B(3) and two equivalent C(1) atoms. There are four inequivalent B sites. In the first B site, B(1) is bonded in a distorted single-bond geometry to one B(4), two equivalent B(3), and one C(1) atom. In the second B site, B(2) is bonded in a distorted single-bond geometry to one B(4), two equivalent B(3), and one C(1) atom. In the third B site, B(3) is bonded in a 8-coordinate geometry to two equivalent Mg(1), one B(2), one B(4), two equivalent B(1), and two equivalent B(3) atoms. In the fourth B site, B(4) is bonded in a 6-coordinate geometry to one B(2), one B(4), two equivalent B(1), and two equivalent B(3) atoms. C(1) is bonded in a 5-coordinate geometry to one Mg(1), one B(2), two equivalent B(1), and one C(1) atom. is represented by the CIF file [CIF]
data_Mg(B6C)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.897
_cell_length_b   6.897
_cell_length_c   6.897
_cell_angle_alpha   132.058
_cell_angle_beta   109.938
_cell_angle_gamma   89.376
_symmetry_Int_Tables_number   1
_cell_volume   217.595
_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  0.387  0.750  0.637  1.0
  Mg  Mg1  1  0.613  0.250  0.363  1.0
  B  B2  1  0.637  0.845  0.312  1.0
  B  B3  1  0.225  0.406  0.819  1.0
  B  B4  1  0.775  0.774  0.678  1.0
  B  B5  1  0.033  0.825  0.688  1.0
  B  B6  1  0.363  0.675  0.208  1.0
  B  B7  1  0.967  0.175  0.312  1.0
  B  B8  1  0.404  0.403  0.678  1.0
  B  B9  1  0.775  0.594  0.181  1.0
  B  B10  1  0.363  0.155  0.688  1.0
  B  B11  1  0.354  0.333  0.021  1.0
  B  B12  1  0.596  0.597  0.322  1.0
  B  B13  1  0.812  0.833  0.979  1.0
  B  B14  1  0.967  0.655  0.792  1.0
  B  B15  1  0.088  0.906  0.181  1.0
  B  B16  1  0.596  0.274  0.999  1.0
  B  B17  1  0.637  0.325  0.792  1.0
  B  B18  1  0.404  0.726  0.001  1.0
  B  B19  1  0.775  0.097  0.001  1.0
  B  B20  1  0.225  0.903  0.999  1.0
  B  B21  1  0.912  0.094  0.819  1.0
  B  B22  1  0.646  0.667  0.979  1.0
  B  B23  1  0.225  0.226  0.322  1.0
  B  B24  1  0.188  0.167  0.021  1.0
  B  B25  1  0.033  0.345  0.208  1.0
  C  C26  1  0.967  0.338  0.629  1.0
  C  C27  1  0.209  0.838  0.371  1.0
  C  C28  1  0.791  0.162  0.629  1.0
  C  C29  1  0.033  0.662  0.371  1.0
[/CIF]
.