data_MgNiSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.04
_cell_length_b   6.04
_cell_length_c   6.04
_cell_angle_alpha   145.0
_cell_angle_beta   145.0
_cell_angle_gamma   50.33
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgNiSe2
_chemical_formula_sum   'Mg1 Ni1 Se2'
_cell_volume   72.13
_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  Mg0  1  0.0  0.0  0.0  1.0
  Ni  Ni1  1  0.82  0.0  0.73  1.0
  Se  Se2  1  0.0  0.0  0.47  1.0
  Se  Se3  1  0.0  0.82  0.73  1.0

data_MgNiSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.63
_cell_length_b   3.63
_cell_length_c   6.04
_cell_angle_alpha   107.5
_cell_angle_beta   107.5
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgNiSe2
_chemical_formula_sum   'Mg1 Ni1 Se2'
_cell_volume   72.13
_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  Mg0  1  0.0  0.0  0.0  1.0
  Ni  Ni1  1  0.27  0.0  0.08  1.0
  Se  Se2  1  0.08  0.82  0.08  1.0
  Se  Se3  1  0.53  0.0  0.53  1.0

Mg Ni Se Se
Mg Ni Se Se 0 1 - o - 0 3 o - - 0 2 o o o 1 3 + - o 1 2 + o o 2 3 o - o 