The material structure described by Co2As crystallizes in the hexagonal P-62m space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent As(1) and two equivalent As(2) atoms to form a mixture of distorted corner and edge-sharing CoAs4 tetrahedra. In the second Co site, Co(2) is bonded in a 5-coordinate geometry to one As(2) and four equivalent As(1) atoms. There are two inequivalent As sites. In the first As site, As(2) is bonded in a 9-coordinate geometry to three equivalent Co(2) and six equivalent Co(1) atoms. In the second As site, As(1) is bonded in a 9-coordinate geometry to three equivalent Co(1) and six equivalent Co(2) atoms. is represented by the CIF file [CIF]
data_Co2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.987
_cell_length_b   5.987
_cell_length_c   3.539
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   109.867
_cell_formula_units_Z   3
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  Co0  1  0.744  0.744  0.000  1.0
  Co  Co1  1  0.256  0.000  0.000  1.0
  Co  Co2  1  0.000  0.256  0.000  1.0
  Co  Co3  1  0.402  0.402  0.500  1.0
  Co  Co4  1  0.598  0.000  0.500  1.0
  Co  Co5  1  0.000  0.598  0.500  1.0
  As  As6  1  0.667  0.333  0.000  1.0
  As  As7  1  0.333  0.667  0.000  1.0
  As  As8  1  0.000  0.000  0.500  1.0
[/CIF]
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The material structure described by Co2As crystallizes in the hexagonal P-62m space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent As(1) and two equivalent As(2) atoms to form a mixture of distorted corner and edge-sharing CoAs4 tetrahedra. In the second Co site, Co(2) is bonded in a 5-coordinate geometry to one As(2) and four equivalent As(1) atoms. There are two inequivalent As sites. In the first As site, As(2) is bonded in a 9-coordinate geometry to three equivalent Co(2) and six equivalent Co(1) atoms. In the second As site, As(1) is bonded in a 9-coordinate geometry to three equivalent Co(1) and six equivalent Co(2) atoms. is represented by the CIF file [CIF]
data_Co2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.987
_cell_length_b   5.987
_cell_length_c   3.539
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   109.867
_cell_formula_units_Z   3
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  Co0  1  0.744  0.744  0.000  1.0
  Co  Co1  1  0.256  0.000  0.000  1.0
  Co  Co2  1  0.000  0.256  0.000  1.0
  Co  Co3  1  0.402  0.402  0.500  1.0
  Co  Co4  1  0.598  0.000  0.500  1.0
  Co  Co5  1  0.000  0.598  0.500  1.0
  As  As6  1  0.667  0.333  0.000  1.0
  As  As7  1  0.333  0.667  0.000  1.0
  As  As8  1  0.000  0.000  0.500  1.0
[/CIF]
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