data_MgZr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.24
_cell_length_b   3.05
_cell_length_c   5.59
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgZr
_chemical_formula_sum   'Mg2 Zr2'
_cell_volume   89.34
_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  0.93  0.0  0.93  1.0
  Mg  Mg1  1  0.31  0.0  0.66  1.0
  Zr  Zr2  1  0.93  0.53  0.71  1.0
  Zr  Zr3  1  0.31  0.53  0.89  1.0

data_MgZr
_symmetry_space_group_name_H-M   P2
_cell_length_a   5.24
_cell_length_b   3.05
_cell_length_c   5.59
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   3
_chemical_formula_structural   MgZr
_chemical_formula_sum   'Mg2 Zr2'
_cell_volume   89.34
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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  2  0.19  0.0  0.36  1.0
  Zr  Zr1  2  0.19  0.53  0.59  1.0

Mg Mg Zr Zr
Mg Mg Zr Zr 0 2 o - o 0 2 o o o 1 3 o - o 1 3 o o o 2 3 + o o 