The material structure described by Mg6AlC crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Al(1), and two equivalent C(1) atoms. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Al(1) atoms to form a mixture of distorted face and corner-sharing MgMg10Al2 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 2-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Al(1) atoms. In the fourth Mg site, Mg(4) is bonded in a 12-coordinate geometry to two equivalent Mg(2) and four equivalent Mg(1) atoms. Al(1) is bonded in a distorted q6 geometry to two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms. C(1) is bonded in a 10-coordinate geometry to four equivalent Mg(1) atoms. is represented by the CIF file [CIF]
data_Mg6AlC
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.980
_cell_length_b   5.897
_cell_length_c   5.959
_cell_angle_alpha   119.654
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   152.068
_cell_formula_units_Z   1
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
  Al  Al0  1  0.000  0.831  0.662  1.0
  C  C1  1  0.500  0.665  0.330  1.0
  Mg  Mg2  1  1.000  0.348  0.177  1.0
  Mg  Mg3  1  0.000  0.828  0.177  1.0
  Mg  Mg4  1  0.000  0.333  0.666  1.0
  Mg  Mg5  1  0.500  0.161  0.827  1.0
  Mg  Mg6  1  0.500  0.667  0.827  1.0
  Mg  Mg7  1  0.500  0.167  0.334  1.0
[/CIF]
.
The material structure described by Mg6AlC crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Al(1), and two equivalent C(1) atoms. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Al(1) atoms to form a mixture of distorted face and corner-sharing MgMg10Al2 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 2-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Al(1) atoms. In the fourth Mg site, Mg(4) is bonded in a 12-coordinate geometry to two equivalent Mg(2) and four equivalent Mg(1) atoms. Al(1) is bonded in a distorted q6 geometry to two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms. C(1) is bonded in a 10-coordinate geometry to four equivalent Mg(1) atoms. is represented by the CIF file [CIF]
data_Mg6AlC
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.980
_cell_length_b   5.897
_cell_length_c   5.959
_cell_angle_alpha   119.654
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   152.068
_cell_formula_units_Z   1
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
  Al  Al0  1  0.000  0.831  0.662  1.0
  C  C1  1  0.500  0.665  0.330  1.0
  Mg  Mg2  1  1.000  0.348  0.177  1.0
  Mg  Mg3  1  0.000  0.828  0.177  1.0
  Mg  Mg4  1  0.000  0.333  0.666  1.0
  Mg  Mg5  1  0.500  0.161  0.827  1.0
  Mg  Mg6  1  0.500  0.667  0.827  1.0
  Mg  Mg7  1  0.500  0.167  0.334  1.0
[/CIF]
.