data_MgSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.68
_cell_length_b   5.68
_cell_length_c   6.79
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgSe3
_chemical_formula_sum   'Mg2 Se6'
_cell_volume   189.57
_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  0.84  0.64  0.1  1.0
  Mg  Mg1  1  0.0  0.28  0.7  1.0
  Se  Se2  1  0.42  0.1  0.1  1.0
  Se  Se3  1  0.58  0.1  0.1  1.0
  Se  Se4  1  0.0  0.64  0.1  1.0
  Se  Se5  1  0.42  0.82  0.7  1.0
  Se  Se6  1  0.26  0.82  0.7  1.0
  Se  Se7  1  0.84  0.28  0.7  1.0

data_MgSe3
_symmetry_space_group_name_H-M   P-1
_cell_length_a   5.68
_cell_length_b   5.68
_cell_length_c   6.79
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   MgSe3
_chemical_formula_sum   'Mg2 Se6'
_cell_volume   189.57
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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  2  0.42  0.18  0.7  1.0
  Se  Se1  2  0.0  0.64  0.7  1.0
  Se  Se2  2  0.16  0.64  0.7  1.0
  Se  Se3  2  0.42  0.82  0.3  1.0

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