data_Si2C
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.75
_cell_length_b   4.75
_cell_length_c   4.75
_cell_angle_alpha   145.77
_cell_angle_beta   140.82
_cell_angle_gamma   52.99
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2C
_chemical_formula_sum   'Si2 C1'
_cell_volume   37.76
_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  Si1  1  0.4  0.0  0.28  1.0
  Si  Si2  1  0.0  0.59  0.97  1.0
  C  C0  1  0.0  0.0  0.0  1.0

data_Si2C
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.79
_cell_length_b   3.18
_cell_length_c   4.75
_cell_angle_alpha   109.59
_cell_angle_beta   107.11
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2C
_chemical_formula_sum   'Si2 C1'
_cell_volume   37.76
_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  0.03  0.62  0.62  1.0
  Si  Si1  1  0.12  0.72  0.12  1.0
  C  C2  1  0.0  0.0  0.0  1.0

Si Si C
Si Si C 0 2 o o o 1 2 o + + 