data_CoAs3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.04
_cell_length_b   3.04
_cell_length_c   8.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CoAs3
_chemical_formula_sum   'Co1 As3'
_cell_volume   69.54
_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
  Co  Co3  1  0.0  0.0  0.0  1.0
  As  As0  1  1.0  0.75  0.66  1.0
  As  As1  1  1.0  0.75  0.05  1.0
  As  As2  1  0.0  0.0  0.35  1.0

data_CoAs3
_symmetry_space_group_name_H-M   Cm
_cell_length_a   3.04
_cell_length_b   5.26
_cell_length_c   8.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   CoAs3
_chemical_formula_sum   'Co2 As6'
_cell_volume   139.09
_cell_formula_units_Z   2
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
  Co  Co0  2  0.0  0.0  0.0  1.0
  As  As1  2  0.0  0.0  0.35  1.0
  As  As2  2  0.25  0.5  0.05  1.0
  As  As3  2  0.25  0.5  0.66  1.0

Co As As As
CoAs3 crystallizes in the monoclinic Cm space group. Co(1) is bonded in a single-bond geometry to one As(1), one As(2), and one As(3) atom. The Co(1)-As(1) bond length is 3.05 Å. The Co(1)-As(2) bond length is 0.86 Å. The Co(1)-As(3) bond length is 3.09 Å. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to one Co(1), one As(3), and six equivalent As(1) atoms. The As(1)-As(3) bond length is 2.77 Å. All As(1)-As(1) bond lengths are 3.04 Å. In the second As site, As(2) is bonded in a single-bond geometry to one Co(1) and one As(3) atom. The As(2)-As(3) bond length is 2.77 Å. In the third As site, As(3) is bonded in a 9-coordinate geometry to one Co(1), one As(1), one As(2), and six equivalent As(3) atoms. All As(3)-As(3) bond lengths are 3.04 Å.