data_AsC
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.58
_cell_length_b   3.58
_cell_length_c   5.02
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   AsC
_chemical_formula_sum   'As2 C2'
_cell_volume   64.38
_cell_formula_units_Z   2
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
  As  As0  1  0.79  0.0  0.12  1.0
  As  As1  1  0.0  0.79  0.91  1.0
  C  C2  1  0.79  0.79  0.0  1.0
  C  C3  1  0.0  0.0  0.0  1.0

data_AsC
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.06
_cell_length_b   5.06
_cell_length_c   5.02
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   AsC
_chemical_formula_sum   'As4 C4'
_cell_volume   128.76
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  As  As0  2  0.0  0.0  0.91  1.0
  As  As1  2  0.29  0.5  0.12  1.0
  C  C2  4  0.39  0.39  0.0  1.0

As As C C
As As C C 0 2 o - o 0 3 + o o 1 2 - o + 1 3 o + + 2 3 + + o 