data_Al2NiSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.23
_cell_length_b   3.24
_cell_length_c   5.99
_cell_angle_alpha   90.0
_cell_angle_beta   99.3
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Al2NiSe
_chemical_formula_sum   'Al2 Ni1 Se1'
_cell_volume   62.06
_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
  Al  Al0  1  0.8  0.62  0.6  1.0
  Al  Al1  1  0.47  0.62  0.31  1.0
  Ni  Ni2  1  0.0  0.0  0.0  1.0
  Se  Se3  1  0.52  0.0  0.96  1.0

data_Al2NiSe
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.23
_cell_length_b   3.24
_cell_length_c   5.99
_cell_angle_alpha   90.0
_cell_angle_beta   99.3
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Al2NiSe
_chemical_formula_sum   'Al2 Ni1 Se1'
_cell_volume   62.06
_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
  Al  Al0  1  0.47  0.62  0.31  1.0
  Al  Al1  1  0.8  0.62  0.6  1.0
  Ni  Ni2  1  0.0  0.0  0.0  1.0
  Se  Se3  1  0.52  0.0  0.96  1.0

Al Al Ni Se
Al Al Ni Se 0 1 o o o 2 3 - o - 2 3 o o - 
NiAl2Se crystallizes in the triclinic P1 space group. Ni(1) is bonded in a distorted bent 150 degrees geometry to one Al(1), three equivalent Al(2), and two equivalent Se(1) atoms. The Ni(1)-Al(1) bond length is 2.66 Å. There is one shorter (2.51 Å) and two longer (2.98 Å) Ni(1)-Al(2) bond lengths. There is one shorter (1.55 Å) and one longer (1.73 Å) Ni(1)-Se(1) bond length. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 3-coordinate geometry to one Ni(1), two equivalent Al(2), and one Se(1) atom. There is one shorter (1.91 Å) and one longer (3.02 Å) Al(1)-Al(2) bond length. The Al(1)-Se(1) bond length is 2.72 Å. In the second Al site, Al(2) is bonded in a 7-coordinate geometry to three equivalent Ni(1), two equivalent Al(1), and two equivalent Se(1) atoms. There is one shorter (2.47 Å) and one longer (2.94 Å) Al(2)-Se(1) bond length. Se(1) is bonded in a 2-coordinate geometry to two equivalent Ni(1), one Al(1), and two equivalent Al(2) atoms.