data_YPSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.94
_cell_length_b   3.6
_cell_length_c   6.78
_cell_angle_alpha   90.0
_cell_angle_beta   103.06
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YPSe2
_chemical_formula_sum   'Y1 P1 Se2'
_cell_volume   93.45
_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
  Y  Y3  1  0.3  0.8  0.26  1.0
  P  P0  1  0.97  0.0  0.68  1.0
  Se  Se1  1  0.06  0.8  0.36  1.0
  Se  Se2  1  0.3  0.0  0.6  1.0

data_YPSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.6
_cell_length_b   3.94
_cell_length_c   6.78
_cell_angle_alpha   103.06
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YPSe2
_chemical_formula_sum   'Y1 P1 Se2'
_cell_volume   93.45
_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
  Y  Y0  1  0.2  0.7  0.74  1.0
  P  P1  1  0.0  0.03  0.32  1.0
  Se  Se2  1  0.0  0.7  0.4  1.0
  Se  Se3  1  0.2  0.94  0.64  1.0

Y P Se Se
Y P Se Se 0 2 o o o 1 3 + o o 2 3 o + o 