data_[Si21C21]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Si  1.9000  1.1000  0.5400
  C  2.5500  0.7000  0.3000
]
_symmetry_space_group_name_H-M [R3m]
_cell_length_a [3.0950]
_cell_length_b [3.0950]
_cell_length_c [53.1317]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [160]
_chemical_formula_structural [SiC]
_chemical_formula_sum '[Si21 C21]'
_cell_volume [440.7563]
_cell_formula_units_Z [21]
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  3  0.0000  0.0000  0.1428  1.0
  Si  Si1  3  0.0000  0.0000  0.2856  1.0
  Si  Si2  3  0.0000  0.0000  0.3809  1.0
  Si  Si3  3  0.0000  0.0000  0.5714  1.0
  Si  Si4  3  0.0000  0.0000  0.7618  1.0
  Si  Si5  3  0.0000  0.0000  0.8572  1.0
  Si  Si6  3  0.0000  0.0000  1.0000  1.0
  C  C7  3  0.0000  0.0000  0.0358  1.0
  C  C8  3  0.0000  0.0000  0.1787  1.0
  C  C9  3  0.0000  0.0000  0.3214  1.0
  C  C10  3  0.0000  0.0000  0.4167  1.0
  C  C11  3  0.0000  0.0000  0.6071  1.0
  C  C12  3  0.0000  0.0000  0.7976  1.0
  C  C13  3  0.0000  0.0000  0.8929  1.0
]