The material described by BiMg2 crystallizes in the trigonal R32 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2) and four equivalent Bi(1) atoms to form distorted MgMg2Bi4 cuboctahedra that share corners with four equivalent Mg(2)Mg6Bi6 cuboctahedra, corners with twelve equivalent Mg(1)Mg2Bi4 cuboctahedra, corners with twelve equivalent Bi(1)Mg9 cuboctahedra, edges with four equivalent Mg(2)Mg6Bi6 cuboctahedra, edges with six equivalent Mg(1)Mg2Bi4 cuboctahedra, and faces with two equivalent Mg(1)Mg2Bi4 cuboctahedra. In the second Mg site, Mg(2) is bonded to six equivalent Mg(1) and six equivalent Bi(1) atoms to form distorted MgMg6Bi6 cuboctahedra that share corners with six equivalent Mg(2)Mg6Bi6 cuboctahedra, corners with six equivalent Bi(1)Mg9 cuboctahedra, corners with twelve equivalent Mg(1)Mg2Bi4 cuboctahedra, edges with six equivalent Mg(2)Mg6Bi6 cuboctahedra, edges with six equivalent Bi(1)Mg9 cuboctahedra, edges with twelve equivalent Mg(1)Mg2Bi4 cuboctahedra, and faces with two equivalent Bi(1)Mg9 cuboctahedra. Bi(1) is bonded to three equivalent Mg(2) and six equivalent Mg(1) atoms to form distorted BiMg9 cuboctahedra that share corners with three equivalent Mg(2)Mg6Bi6 cuboctahedra, corners with eighteen equivalent Mg(1)Mg2Bi4 cuboctahedra, corners with eighteen equivalent Bi(1)Mg9 cuboctahedra, edges with three equivalent Mg(2)Mg6Bi6 cuboctahedra,  a faceface with one Mg(2)Mg6Bi6 cuboctahedra, and faces with four equivalent Bi(1)Mg9 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2Bi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.319
_cell_length_b   6.319
_cell_length_c   6.319
_cell_angle_alpha   54.595
_cell_angle_beta   54.595
_cell_angle_gamma   54.595
_symmetry_Int_Tables_number   1
_cell_volume   155.920
_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  0.336  0.000  0.664  1.0
  Mg  Mg1  1  0.000  0.664  0.336  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.664  0.336  0.000  1.0
  Bi  Bi4  1  0.836  0.836  0.836  1.0
  Bi  Bi5  1  0.164  0.164  0.164  1.0
[/CIF]
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The material described by BiMg2 crystallizes in the trigonal R32 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2) and four equivalent Bi(1) atoms to form distorted MgMg2Bi4 cuboctahedra that share corners with four equivalent Mg(2)Mg6Bi6 cuboctahedra, corners with twelve equivalent Mg(1)Mg2Bi4 cuboctahedra, corners with twelve equivalent Bi(1)Mg9 cuboctahedra, edges with four equivalent Mg(2)Mg6Bi6 cuboctahedra, edges with six equivalent Mg(1)Mg2Bi4 cuboctahedra, and faces with two equivalent Mg(1)Mg2Bi4 cuboctahedra. In the second Mg site, Mg(2) is bonded to six equivalent Mg(1) and six equivalent Bi(1) atoms to form distorted MgMg6Bi6 cuboctahedra that share corners with six equivalent Mg(2)Mg6Bi6 cuboctahedra, corners with six equivalent Bi(1)Mg9 cuboctahedra, corners with twelve equivalent Mg(1)Mg2Bi4 cuboctahedra, edges with six equivalent Mg(2)Mg6Bi6 cuboctahedra, edges with six equivalent Bi(1)Mg9 cuboctahedra, edges with twelve equivalent Mg(1)Mg2Bi4 cuboctahedra, and faces with two equivalent Bi(1)Mg9 cuboctahedra. Bi(1) is bonded to three equivalent Mg(2) and six equivalent Mg(1) atoms to form distorted BiMg9 cuboctahedra that share corners with three equivalent Mg(2)Mg6Bi6 cuboctahedra, corners with eighteen equivalent Mg(1)Mg2Bi4 cuboctahedra, corners with eighteen equivalent Bi(1)Mg9 cuboctahedra, edges with three equivalent Mg(2)Mg6Bi6 cuboctahedra,  a faceface with one Mg(2)Mg6Bi6 cuboctahedra, and faces with four equivalent Bi(1)Mg9 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2Bi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.319
_cell_length_b   6.319
_cell_length_c   6.319
_cell_angle_alpha   54.595
_cell_angle_beta   54.595
_cell_angle_gamma   54.595
_symmetry_Int_Tables_number   1
_cell_volume   155.920
_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  0.336  0.000  0.664  1.0
  Mg  Mg1  1  0.000  0.664  0.336  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.664  0.336  0.000  1.0
  Bi  Bi4  1  0.836  0.836  0.836  1.0
  Bi  Bi5  1  0.164  0.164  0.164  1.0
[/CIF]
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