data_Ti2NiAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.69
_cell_length_b   4.69
_cell_length_c   4.69
_cell_angle_alpha   133.78
_cell_angle_beta   129.26
_cell_angle_gamma   71.05
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ti2NiAs
_chemical_formula_sum   'Ti2 Ni1 As1'
_cell_volume   56.39
_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
  Ti  Ti2  1  0.84  0.0  0.89  1.0
  Ti  Ti3  1  0.0  0.01  0.92  1.0
  Ni  Ni1  1  0.0  0.0  0.0  1.0
  As  As0  1  0.0  0.0  0.82  1.0

data_Ti2NiAs
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.68
_cell_length_b   4.02
_cell_length_c   4.69
_cell_angle_alpha   115.37
_cell_angle_beta   113.11
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ti2NiAs
_chemical_formula_sum   'Ti2 Ni1 As1'
_cell_volume   56.39
_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
  Ti  Ti0  1  0.08  0.08  0.08  1.0
  Ti  Ti1  1  0.95  0.11  0.95  1.0
  Ni  Ni2  1  0.0  0.0  0.0  1.0
  As  As3  1  0.18  0.18  0.18  1.0

Ti Ti Ni As
Ti Ti Ni As 0 1 + o o 0 2 + o + 1 2 o o + 1 3 o o o 
Ti2NiAs crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one Ti2NiAs cluster. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 2-coordinate geometry to one Ti(2) and one Ni(1) atom. The Ti(1)-Ti(2) bond length is 0.67 Å. The Ti(1)-Ni(1) bond length is 0.58 Å. In the second Ti site, Ti(2) is bonded in a distorted linear geometry to one Ti(1), one Ni(1), and one As(1) atom. The Ti(2)-Ni(1) bond length is 0.38 Å. The Ti(2)-As(1) bond length is 0.49 Å. Ni(1) is bonded in an L-shaped geometry to one Ti(1) and one Ti(2) atom. As(1) is bonded in a single-bond geometry to one Ti(2) atom.