data_Nb2NiAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.51
_cell_length_b   4.51
_cell_length_c   3.11
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   103.21
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Nb2NiAs
_chemical_formula_sum   'Nb2 Ni1 As1'
_cell_volume   61.58
_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
  Nb  Nb1  1  0.4  0.23  0.55  1.0
  Nb  Nb2  1  0.4  0.77  0.55  1.0
  Ni  Ni3  1  0.0  0.0  0.0  1.0
  As  As0  1  0.8  0.0  0.0  1.0

data_Nb2NiAs
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.11
_cell_length_b   4.51
_cell_length_c   4.51
_cell_angle_alpha   103.21
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Nb2NiAs
_chemical_formula_sum   'Nb2 Ni1 As1'
_cell_volume   61.58
_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
  Nb  Nb0  1  0.55  0.4  0.23  1.0
  Nb  Nb1  1  0.55  0.4  0.77  1.0
  Ni  Ni2  1  0.0  0.0  0.0  1.0
  As  As3  1  -0.0  0.8  0.0  1.0

Nb Nb Ni As
Nb2NiAs crystallizes in the triclinic P1 space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to two equivalent Nb(2), two equivalent Ni(1), and two equivalent As(1) atoms. There is one shorter (2.09 Å) and one longer (2.42 Å) Nb(1)-Nb(2) bond length. There is one shorter (2.33 Å) and one longer (2.54 Å) Nb(1)-Ni(1) bond length. There is one shorter (2.68 Å) and one longer (2.86 Å) Nb(1)-As(1) bond length. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to two equivalent Nb(1), two equivalent Ni(1), and two equivalent As(1) atoms. There is one shorter (2.68 Å) and one longer (2.86 Å) Nb(2)-Ni(1) bond length. There is one shorter (2.33 Å) and one longer (2.54 Å) Nb(2)-As(1) bond length. Ni(1) is bonded in a distorted single-bond geometry to two equivalent Nb(1), two equivalent Nb(2), and one As(1) atom. The Ni(1)-As(1) bond length is 0.89 Å. As(1) is bonded in a distorted single-bond geometry to two equivalent Nb(1), two equivalent Nb(2), and one Ni(1) atom.