data_TiNiSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.36
_cell_length_b   3.25
_cell_length_c   6.31
_cell_angle_alpha   90.0
_cell_angle_beta   103.57
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TiNiSe2
_chemical_formula_sum   'Ti1 Ni1 Se2'
_cell_volume   67.06
_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  Ti3  1  0.0  0.0  0.0  1.0
  Ni  Ni0  1  0.26  0.0  0.07  1.0
  Se  Se1  1  0.02  0.63  0.65  1.0
  Se  Se2  1  0.86  0.63  0.49  1.0

data_TiNiSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.25
_cell_length_b   3.36
_cell_length_c   6.31
_cell_angle_alpha   103.57
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TiNiSe2
_chemical_formula_sum   'Ti1 Ni1 Se2'
_cell_volume   67.06
_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  0.0  0.0  0.0  1.0
  Ni  Ni1  1  0.0  0.74  0.93  1.0
  Se  Se2  1  0.37  0.14  0.51  1.0
  Se  Se3  1  0.37  0.98  0.35  1.0

Ti Ni Se Se
Ti Ni Se Se 0 1 o o o 2 3 - o o 
TiNiSe2 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one TiNiSe2 cluster. Ti(1) is bonded in a distorted single-bond geometry to one Ni(1) and one Se(1) atom. The Ti(1)-Ni(1) bond length is 0.88 Å. The Ti(1)-Se(1) bond length is 2.55 Å. Ni(1) is bonded in a single-bond geometry to one Ti(1) atom. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 2-coordinate geometry to one Ti(1) and one Se(2) atom. The Se(1)-Se(2) bond length is 1.01 Å. In the second Se site, Se(2) is bonded in a single-bond geometry to one Se(1) atom.