data_MgZnSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.5
_cell_length_b   4.5
_cell_length_c   10.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgZnSe2
_chemical_formula_sum   'Mg2 Zn2 Se4'
_cell_volume   202.73
_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  0.25  0.0  0.77  1.0
  Mg  Mg1  1  0.0  0.25  0.24  1.0
  Zn  Zn6  1  0.25  0.0  0.89  1.0
  Zn  Zn7  1  0.0  0.25  0.12  1.0
  Se  Se2  1  0.25  0.0  0.41  1.0
  Se  Se3  1  0.0  0.25  0.6  1.0
  Se  Se4  1  0.0  0.0  0.0  1.0
  Se  Se5  1  0.25  0.25  0.0  1.0

data_MgZnSe2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.36
_cell_length_b   6.36
_cell_length_c   10.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgZnSe2
_chemical_formula_sum   'Mg4 Zn4 Se8'
_cell_volume   405.45
_cell_formula_units_Z   4
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  0.24  1.0
  Mg  Mg1  2  0.25  0.0  0.77  1.0
  Zn  Zn2  2  0.0  0.0  0.12  1.0
  Zn  Zn3  2  0.25  0.0  0.89  1.0
  Se  Se4  4  0.13  0.13  0.0  1.0
  Se  Se5  2  0.0  0.0  0.6  1.0
  Se  Se6  2  0.25  0.0  0.41  1.0

Mg Mg Zn Zn Se Se Se Se
Mg Mg Zn Zn Se Se Se Se 0 2 o o o 0 5 o o o 1 3 o o o 1 4 o o o 2 6 o o + 2 7 o o + 3 6 o o o 3 7 o o o 4 5 o o o 6 7 o o o 