data_CaSiSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.27
_cell_length_b   5.27
_cell_length_c   5.27
_cell_angle_alpha   134.42
_cell_angle_beta   113.27
_cell_angle_gamma   84.55
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaSiSe2
_chemical_formula_sum   'Ca1 Si1 Se2'
_cell_volume   92.41
_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
  Ca  Ca0  1  0.0  0.0  0.9  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0
  Se  Se1  1  0.0  0.9  0.2  1.0
  Se  Se2  1  0.04  0.0  0.71  1.0

data_CaSiSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.08
_cell_length_b   5.27
_cell_length_c   5.27
_cell_angle_alpha   66.73
_cell_angle_beta   67.21
_cell_angle_gamma   67.21
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaSiSe2
_chemical_formula_sum   'Ca1 Si1 Se2'
_cell_volume   92.41
_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
  Ca  Ca0  1  0.9  0.0  0.1  1.0
  Si  Si1  1  0.0  0.0  0.0  1.0
  Se  Se2  1  0.2  -0.0  0.7  1.0
  Se  Se3  1  0.66  0.04  0.29  1.0

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