data_MgCuSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.15
_cell_length_b   4.15
_cell_length_c   10.79
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgCuSe2
_chemical_formula_sum   'Mg2 Cu2 Se4'
_cell_volume   186.2
_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  Mg2  1  0.08  0.0  0.14  1.0
  Mg  Mg3  1  0.0  0.08  0.66  1.0
  Cu  Cu0  1  0.08  0.0  0.27  1.0
  Cu  Cu1  1  0.0  0.08  0.53  1.0
  Se  Se4  1  0.08  0.0  0.7  1.0
  Se  Se5  1  0.0  0.08  0.09  1.0
  Se  Se6  1  0.0  0.0  0.0  1.0
  Se  Se7  1  0.08  0.08  0.0  1.0

data_MgCuSe2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.87
_cell_length_b   5.87
_cell_length_c   10.79
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgCuSe2
_chemical_formula_sum   'Mg4 Cu4 Se8'
_cell_volume   372.4
_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  0.66  1.0
  Mg  Mg1  2  0.08  0.0  0.14  1.0
  Cu  Cu2  2  0.0  0.0  0.53  1.0
  Cu  Cu3  2  0.08  0.0  0.27  1.0
  Se  Se4  4  0.04  0.04  0.0  1.0
  Se  Se5  2  0.0  0.0  0.09  1.0
  Se  Se6  2  0.08  0.0  0.7  1.0

Mg Mg Cu Cu Se Se Se Se