data_NaTiSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.79
_cell_length_b   4.79
_cell_length_c   3.37
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaTiSe2
_chemical_formula_sum   'Na1 Ti1 Se2'
_cell_volume   77.39
_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
  Na  Na0  1  0.0  0.0  0.0  1.0
  Ti  Ti3  1  0.4  0.4  0.0  1.0
  Se  Se1  1  0.0  0.4  0.68  1.0
  Se  Se2  1  0.4  0.0  0.68  1.0

data_NaTiSe2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.78
_cell_length_b   6.78
_cell_length_c   3.37
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NaTiSe2
_chemical_formula_sum   'Na2 Ti2 Se4'
_cell_volume   154.78
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Na  Na0  2  0.0  0.0  0.0  1.0
  Ti  Ti1  2  0.4  0.0  -0.0  1.0
  Se  Se2  4  0.2  0.2  0.68  1.0

Na Ti Se Se
NaTiSe2 crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two NaTiSe2 clusters. Na(1) is bonded in a 2-coordinate geometry to two equivalent Se(1) atoms. Both Na(1)-Se(1) bond lengths are 2.18 Å. Ti(1) is bonded in a 2-coordinate geometry to two equivalent Se(1) atoms. Both Ti(1)-Se(1) bond lengths are 2.18 Å. Se(1) is bonded in a 2-coordinate geometry to one Na(1) and one Ti(1) atom.