data_Ni3As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.08
_cell_length_b   5.08
_cell_length_c   4.09
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ni3As
_chemical_formula_sum   'Ni6 As2'
_cell_volume   91.27
_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  Ni2  1  0.0  0.47  0.07  1.0
  Ni  Ni3  1  0.27  0.66  0.07  1.0
  Ni  Ni4  1  0.73  0.66  0.07  1.0
  Ni  Ni5  1  0.54  0.93  0.02  1.0
  Ni  Ni6  1  0.27  0.73  0.02  1.0
  Ni  Ni7  1  0.81  0.73  0.02  1.0
  As  As0  1  0.0  0.93  0.02  1.0
  As  As1  1  0.54  0.47  0.07  1.0

data_Ni3As
_symmetry_space_group_name_H-M   P-1
_cell_length_a   4.09
_cell_length_b   5.08
_cell_length_c   5.08
_cell_angle_alpha   120.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Ni3As
_chemical_formula_sum   'Ni6 As2'
_cell_volume   91.27
_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  0.02  0.46  0.46  1.0
  Ni  Ni1  2  0.02  0.73  0.27  1.0
  Ni  Ni2  2  0.02  1.0  0.46  1.0
  As  As3  2  0.02  0.27  0.27  1.0

Ni Ni Ni Ni Ni Ni As As
Ni Ni Ni Ni Ni Ni As As 0 4 o o o 0 1 o o o 1 4 o o o 1 3 o o o 2 5 o o o 2 7 o o o 3 4 o o o 5 6 + o o 
(Ni)2NiAs crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one Ni cluster and one NiAs cluster. In the Ni cluster, there are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 1-coordinate geometry to one Ni(2) atom. The Ni(1)-Ni(2) bond length is 1.22 Å. In the second Ni site, Ni(2) is bonded in a distorted single-bond geometry to one Ni(1) and one Ni(2) atom. The Ni(2)-Ni(2) bond length is 0.39 Å. In the NiAs cluster, Ni(3) is bonded in a bent 150 degrees geometry to one Ni(3) and one As(1) atom. The Ni(3)-Ni(3) bond length is 0.41 Å. The Ni(3)-As(1) bond length is 0.99 Å. As(1) is bonded in a distorted single-bond geometry to one Ni(3) atom.