data_Si2MoSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.14
_cell_length_b   4.17
_cell_length_c   4.79
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2MoSe
_chemical_formula_sum   'Si2 Mo1 Se1'
_cell_volume   62.86
_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
  Si  Si2  1  0.57  0.09  0.0  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0
  Mo  Mo0  1  0.0  0.09  0.4  1.0
  Se  Se1  1  0.57  0.0  0.4  1.0

data_Si2MoSe
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.14
_cell_length_b   4.17
_cell_length_c   4.79
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2MoSe
_chemical_formula_sum   'Si2 Mo1 Se1'
_cell_volume   62.86
_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
  Si  Si0  1  0.0  0.0  0.0  1.0
  Si  Si1  1  0.57  0.09  0.0  1.0
  Mo  Mo2  1  0.0  0.09  0.4  1.0
  Se  Se3  1  0.57  0.0  0.4  1.0

Si Si Mo Se
Si Si Mo Se 0 1 + o o 2 3 - o o 