data_TcNi2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.7
_cell_length_b   4.7
_cell_length_c   4.7
_cell_angle_alpha   134.0
_cell_angle_beta   134.0
_cell_angle_gamma   67.08
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TcNi2Se
_chemical_formula_sum   'Tc1 Ni2 Se1'
_cell_volume   52.88
_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
  Tc  Tc3  1  0.0  0.0  0.92  1.0
  Ni  Ni0  1  0.0  0.84  0.96  1.0
  Ni  Ni1  1  0.84  0.0  0.96  1.0
  Se  Se2  1  0.0  0.0  0.0  1.0

data_TcNi2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.2
_cell_length_b   5.2
_cell_length_c   4.7
_cell_angle_alpha   90.0
_cell_angle_beta   123.54
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   TcNi2Se
_chemical_formula_sum   'Tc2 Ni4 Se2'
_cell_volume   105.76
_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
  Tc  Tc0  2  0.08  0.0  0.08  1.0
  Ni  Ni1  4  0.46  0.42  0.88  1.0
  Se  Se2  2  0.0  0.0  0.0  1.0

Tc Ni Ni Se
TcNi2Se is Ammonia-derived structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two TcNi2Se clusters. Tc(1) is bonded in a single-bond geometry to one Se(1) atom. The Tc(1)-Se(1) bond length is 0.38 Å. Ni(1) is bonded in a single-bond geometry to one Se(1) atom. The Ni(1)-Se(1) bond length is 0.65 Å. Se(1) is bonded in a distorted trigonal planar geometry to one Tc(1) and two equivalent Ni(1) atoms.