The compound described by Na3Mg is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to eight equivalent Na(2) and four equivalent Mg(1) atoms to form distorted NaNa8Mg4 cuboctahedra that share corners with four equivalent Na(1)Na8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Na12 cuboctahedra, edges with eight equivalent Na(1)Na8Mg4 cuboctahedra, edges with sixteen equivalent Na(2)Na8Mg4 cuboctahedra, faces with four equivalent Na(1)Na8Mg4 cuboctahedra, faces with six equivalent Mg(1)Na12 cuboctahedra, and faces with eight equivalent Na(2)Na8Mg4 cuboctahedra. In the second Na site, Na(2) is bonded to four equivalent Na(1), four equivalent Na(2), and four equivalent Mg(1) atoms to form NaNa8Mg4 cuboctahedra that share corners with twelve equivalent Na(2)Na8Mg4 cuboctahedra, edges with eight equivalent Na(1)Na8Mg4 cuboctahedra, edges with eight equivalent Na(2)Na8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Na12 cuboctahedra, faces with four equivalent Na(1)Na8Mg4 cuboctahedra, faces with four equivalent Mg(1)Na12 cuboctahedra, and faces with ten equivalent Na(2)Na8Mg4 cuboctahedra. Mg(1) is bonded to four equivalent Na(1) and eight equivalent Na(2) atoms to form MgNa12 cuboctahedra that share corners with four equivalent Mg(1)Na12 cuboctahedra, corners with eight equivalent Na(1)Na8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Na12 cuboctahedra, edges with sixteen equivalent Na(2)Na8Mg4 cuboctahedra, faces with four equivalent Mg(1)Na12 cuboctahedra, faces with six equivalent Na(1)Na8Mg4 cuboctahedra, and faces with eight equivalent Na(2)Na8Mg4 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na3Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.292
_cell_length_b   6.292
_cell_length_c   6.292
_cell_angle_alpha   133.756
_cell_angle_beta   133.756
_cell_angle_gamma   67.469
_symmetry_Int_Tables_number   1
_cell_volume   127.771
_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
  Na  Na0  1  0.500  0.500  0.000  1.0
  Na  Na1  1  0.750  0.250  0.500  1.0
  Na  Na2  1  0.250  0.750  0.500  1.0
  Mg  Mg3  1  0.000  0.000  0.000  1.0
[/CIF]
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The compound described by Na3Mg is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to eight equivalent Na(2) and four equivalent Mg(1) atoms to form distorted NaNa8Mg4 cuboctahedra that share corners with four equivalent Na(1)Na8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Na12 cuboctahedra, edges with eight equivalent Na(1)Na8Mg4 cuboctahedra, edges with sixteen equivalent Na(2)Na8Mg4 cuboctahedra, faces with four equivalent Na(1)Na8Mg4 cuboctahedra, faces with six equivalent Mg(1)Na12 cuboctahedra, and faces with eight equivalent Na(2)Na8Mg4 cuboctahedra. In the second Na site, Na(2) is bonded to four equivalent Na(1), four equivalent Na(2), and four equivalent Mg(1) atoms to form NaNa8Mg4 cuboctahedra that share corners with twelve equivalent Na(2)Na8Mg4 cuboctahedra, edges with eight equivalent Na(1)Na8Mg4 cuboctahedra, edges with eight equivalent Na(2)Na8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Na12 cuboctahedra, faces with four equivalent Na(1)Na8Mg4 cuboctahedra, faces with four equivalent Mg(1)Na12 cuboctahedra, and faces with ten equivalent Na(2)Na8Mg4 cuboctahedra. Mg(1) is bonded to four equivalent Na(1) and eight equivalent Na(2) atoms to form MgNa12 cuboctahedra that share corners with four equivalent Mg(1)Na12 cuboctahedra, corners with eight equivalent Na(1)Na8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Na12 cuboctahedra, edges with sixteen equivalent Na(2)Na8Mg4 cuboctahedra, faces with four equivalent Mg(1)Na12 cuboctahedra, faces with six equivalent Na(1)Na8Mg4 cuboctahedra, and faces with eight equivalent Na(2)Na8Mg4 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na3Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.292
_cell_length_b   6.292
_cell_length_c   6.292
_cell_angle_alpha   133.756
_cell_angle_beta   133.756
_cell_angle_gamma   67.469
_symmetry_Int_Tables_number   1
_cell_volume   127.771
_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
  Na  Na0  1  0.500  0.500  0.000  1.0
  Na  Na1  1  0.750  0.250  0.500  1.0
  Na  Na2  1  0.250  0.750  0.500  1.0
  Mg  Mg3  1  0.000  0.000  0.000  1.0
[/CIF]
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