data_[Mg2Ni2Se2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  Ni  1.9100  1.3500  0.7400
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Pmm2]
_cell_length_a [3.6018]
_cell_length_b [5.2258]
_cell_length_c [5.5076]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [25]
_chemical_formula_structural [MgNiSe]
_chemical_formula_sum '[Mg2 Ni2 Se2]'
_cell_volume [103.6662]
_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  0.5000  0.0000  0.6008  1
  Mg  Mg1  1  0.5000  0.5000  0.1815  1
  Ni  Ni2  2  0.0000  0.2603  0.8858  1
  Se  Se3  1  0.0000  0.0000  0.2199  1
  Se  Se4  1  0.5000  0.5000  0.6752  1
]