The compound described by Mg2Ga 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), six equivalent Mg(1), and four equivalent Ga(1) atoms to form distorted MgMg8Ga4 cuboctahedra that share corners with eighteen equivalent Mg(1)Mg8Ga4 cuboctahedra, edges with four equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with six equivalent Mg(1)Mg8Ga4 cuboctahedra, faces with four equivalent Mg(2)Mg6Ga6 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Ga4 cuboctahedra. In the second Mg site, Mg(2) is bonded to six equivalent Mg(1) and six equivalent Ga(1) atoms to form MgMg6Ga6 cuboctahedra that share corners with six equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with six equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with twelve equivalent Mg(1)Mg8Ga4 cuboctahedra, and faces with twelve equivalent Mg(1)Mg8Ga4 cuboctahedra. Ga(1) is bonded in a 9-coordinate geometry to three equivalent Mg(2) and six equivalent Mg(1) atoms. is represented by the CIF card [CIF]
data_Mg2Ga
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.746
_cell_length_b   5.746
_cell_length_c   5.746
_cell_angle_alpha   55.465
_cell_angle_beta   55.465
_cell_angle_gamma   55.465
_symmetry_Int_Tables_number   1
_cell_volume   120.023
_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  0.329  0.000  0.671  1.0
  Mg  Mg1  1  0.000  0.671  0.329  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.671  0.329  0.000  1.0
  Ga  Ga4  1  0.835  0.835  0.835  1.0
  Ga  Ga5  1  0.165  0.165  0.165  1.0
[/CIF]
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The compound described by Mg2Ga 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), six equivalent Mg(1), and four equivalent Ga(1) atoms to form distorted MgMg8Ga4 cuboctahedra that share corners with eighteen equivalent Mg(1)Mg8Ga4 cuboctahedra, edges with four equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with six equivalent Mg(1)Mg8Ga4 cuboctahedra, faces with four equivalent Mg(2)Mg6Ga6 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Ga4 cuboctahedra. In the second Mg site, Mg(2) is bonded to six equivalent Mg(1) and six equivalent Ga(1) atoms to form MgMg6Ga6 cuboctahedra that share corners with six equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with six equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with twelve equivalent Mg(1)Mg8Ga4 cuboctahedra, and faces with twelve equivalent Mg(1)Mg8Ga4 cuboctahedra. Ga(1) is bonded in a 9-coordinate geometry to three equivalent Mg(2) and six equivalent Mg(1) atoms. is represented by the CIF card [CIF]
data_Mg2Ga
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.746
_cell_length_b   5.746
_cell_length_c   5.746
_cell_angle_alpha   55.465
_cell_angle_beta   55.465
_cell_angle_gamma   55.465
_symmetry_Int_Tables_number   1
_cell_volume   120.023
_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  0.329  0.000  0.671  1.0
  Mg  Mg1  1  0.000  0.671  0.329  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.671  0.329  0.000  1.0
  Ga  Ga4  1  0.835  0.835  0.835  1.0
  Ga  Ga5  1  0.165  0.165  0.165  1.0
[/CIF]
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