data_Mg4CuSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.26
_cell_length_b   7.26
_cell_length_c   7.26
_cell_angle_alpha   105.35
_cell_angle_beta   105.35
_cell_angle_gamma   118.06
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg4CuSe8
_chemical_formula_sum   'Mg4 Cu1 Se8'
_cell_volume   290.12
_cell_formula_units_Z   1
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  Mg1  1  0.8  0.2  0.87  1.0
  Mg  Mg2  1  0.2  0.8  0.87  1.0
  Mg  Mg3  1  0.2  0.2  0.13  1.0
  Mg  Mg4  1  0.2  0.2  0.87  1.0
  Cu  Cu0  1  0.0  0.0  0.0  1.0
  Se  Se5  1  0.0  0.43  0.0  1.0
  Se  Se6  1  0.0  0.38  0.0  1.0
  Se  Se7  1  0.38  0.0  0.0  1.0
  Se  Se8  1  0.43  0.0  0.0  1.0
  Se  Se9  1  0.4  0.44  0.0  1.0
  Se  Se10  1  0.0  0.97  0.74  1.0
  Se  Se11  1  0.97  0.0  0.74  1.0
  Se  Se12  1  0.44  0.4  0.0  1.0

data_Mg4CuSe8
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.48
_cell_length_b   12.46
_cell_length_c   7.26
_cell_angle_alpha   90.0
_cell_angle_beta   120.97
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Mg4CuSe8
_chemical_formula_sum   'Mg8 Cu2 Se16'
_cell_volume   580.25
_cell_formula_units_Z   2
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  4  0.13  0.2  0.13  1.0
  Mg  Mg1  2  0.07  0.0  0.87  1.0
  Mg  Mg2  2  0.33  0.0  0.13  1.0
  Cu  Cu3  2  0.0  0.0  0.0  1.0
  Se  Se4  4  0.19  0.19  -0.0  1.0
  Se  Se5  4  0.21  0.21  -0.0  1.0
  Se  Se6  4  0.25  0.02  0.26  1.0
  Se  Se7  4  0.42  0.02  -0.0  1.0

Mg Mg Mg Mg Cu Se Se Se Se Se Se Se Se