data_Mg2Ag
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.57
_cell_length_b   5.57
_cell_length_c   5.57
_cell_angle_alpha   144.17
_cell_angle_beta   144.17
_cell_angle_gamma   51.57
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2Ag
_chemical_formula_sum   'Mg2 Ag1'
_cell_volume   58.98
_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
  Mg  Mg1  1  0.0  0.0  0.57  1.0
  Mg  Mg2  1  0.0  0.0  0.47  1.0
  Ag  Ag0  1  0.0  0.0  0.0  1.0

data_Mg2Ag
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.85
_cell_length_b   4.85
_cell_length_c   5.57
_cell_angle_alpha   90.0
_cell_angle_beta   115.79
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Mg2Ag
_chemical_formula_sum   'Mg4 Ag2'
_cell_volume   117.96
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.43  1.0
  Mg  Mg1  2  0.0  0.0  0.53  1.0
  Ag  Ag2  2  0.0  0.0  0.0  1.0

Mg Mg Ag
Mg Mg Ag 0 1 o o o 0 2 o o + 1 2 o o + 1 2 o o o 