data_[Zn2Se2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Zn  1.6500  1.3500  0.8800
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Pmm2]
_cell_length_a [2.8319]
_cell_length_b [8.1613]
_cell_length_c [17.1794]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [25]
_chemical_formula_structural [ZnSe]
_chemical_formula_sum '[Zn2 Se2]'
_cell_volume [397.0456]
_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
[
  Zn  Zn0  1  0.5000  0.0000  0.4074  1
  Zn  Zn1  1  0.5000  0.5000  0.5242  1
  Se  Se2  2  0.5000  0.2206  0.5342  1
]