data_MgCu3Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.14
_cell_length_b   7.14
_cell_length_c   7.14
_cell_angle_alpha   151.94
_cell_angle_beta   151.94
_cell_angle_gamma   40.1
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgCu3Se
_chemical_formula_sum   'Mg1 Cu3 Se1'
_cell_volume   80.47
_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  Mg3  1  0.0  0.0  0.49  1.0
  Cu  Cu0  1  0.0  0.73  0.05  1.0
  Cu  Cu1  1  0.73  0.0  0.05  1.0
  Cu  Cu2  1  0.0  0.0  0.21  1.0
  Se  Se4  1  0.0  0.0  0.7  1.0

data_MgCu3Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.9
_cell_length_b   4.9
_cell_length_c   7.14
_cell_angle_alpha   90.0
_cell_angle_beta   110.05
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgCu3Se
_chemical_formula_sum   'Mg2 Cu6 Se2'
_cell_volume   160.94
_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  2  0.49  0.0  0.49  1.0
  Cu  Cu1  4  0.19  0.13  0.32  1.0
  Cu  Cu2  2  0.21  0.0  0.21  1.0
  Se  Se3  2  0.2  0.5  0.7  1.0

Mg Cu Cu Cu Se
Mg Cu Cu Cu Se 0 2 - o o 0 1 o - o 0 4 o o o 1 3 o + o 1 2 - + o 2 3 + o o 