data_Ni3As2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.67
_cell_length_b   5.67
_cell_length_c   5.67
_cell_angle_alpha   64.93
_cell_angle_beta   64.93
_cell_angle_gamma   64.93
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ni3As2
_chemical_formula_sum   'Ni6 As4'
_cell_volume   142.51
_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
  Ni  Ni4  1  0.49  0.0  0.0  1.0
  Ni  Ni5  1  0.76  0.31  0.0  1.0
  Ni  Ni6  1  0.76  0.69  0.0  1.0
  Ni  Ni7  1  0.24  0.69  0.33  1.0
  Ni  Ni8  1  0.51  0.0  0.33  1.0
  Ni  Ni9  1  0.24  0.31  0.33  1.0
  As  As0  1  0.0  0.0  0.19  1.0
  As  As1  1  0.0  0.0  0.48  1.0
  As  As2  1  0.0  0.0  0.86  1.0
  As  As3  1  0.0  0.0  0.15  1.0

data_Ni3As2
_symmetry_space_group_name_H-M   P-1
_cell_length_a   5.67
_cell_length_b   5.67
_cell_length_c   5.67
_cell_angle_alpha   64.93
_cell_angle_beta   64.93
_cell_angle_gamma   64.93
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Ni3As2
_chemical_formula_sum   'Ni6 As4'
_cell_volume   142.51
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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
  Ni  Ni0  2  0.0  0.49  0.33  1.0
  Ni  Ni1  2  0.31  0.24  0.67  1.0
  Ni  Ni2  2  0.31  0.76  0.33  1.0
  As  As3  2  0.0  0.0  0.19  1.0
  As  As4  2  0.0  0.0  0.48  1.0

Ni Ni Ni Ni Ni Ni As As As As
Ni3As2 crystallizes in the triclinic P-1 space group. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a distorted L-shaped geometry to one Ni(1), one Ni(3), and one As(2) atom. The Ni(1)-Ni(1) bond length is 1.95 Å. The Ni(1)-Ni(3) bond length is 1.79 Å. The Ni(1)-As(2) bond length is 2.68 Å. In the second Ni site, Ni(2) is bonded in a 2-coordinate geometry to one Ni(3), one As(1), and one As(2) atom. The Ni(2)-Ni(3) bond length is 2.13 Å. The Ni(2)-As(1) bond length is 1.82 Å. The Ni(2)-As(2) bond length is 1.96 Å. In the third Ni site, Ni(3) is bonded in a 4-coordinate geometry to one Ni(1), one Ni(2), and two equivalent As(2) atoms. There is one shorter (2.36 Å) and one longer (2.84 Å) Ni(3)-As(2) bond length. There are two inequivalent As sites. In the first As site, As(1) is bonded in a single-bond geometry to one Ni(2), one As(1), and one As(2) atom. The As(1)-As(1) bond length is 0.28 Å. The As(1)-As(2) bond length is 1.59 Å. In the second As site, As(2) is bonded in a 6-coordinate geometry to one Ni(1), one Ni(2), two equivalent Ni(3), one As(1), and one As(2) atom. The As(2)-As(2) bond length is 2.20 Å.