data_Nb2AlCr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.3
_cell_length_b   4.3
_cell_length_c   3.43
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Nb2AlCr
_chemical_formula_sum   'Nb2 Al1 Cr1'
_cell_volume   63.29
_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
  Nb  Nb2  1  0.15  0.0  0.71  1.0
  Nb  Nb3  1  0.0  0.15  0.71  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0
  Cr  Cr1  1  0.15  0.15  0.0  1.0

data_Nb2AlCr
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.08
_cell_length_b   6.08
_cell_length_c   3.43
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Nb2AlCr
_chemical_formula_sum   'Nb4 Al2 Cr2'
_cell_volume   126.57
_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
  Nb  Nb0  4  0.07  0.07  0.71  1.0
  Al  Al1  2  0.0  0.0  0.0  1.0
  Cr  Cr2  2  0.15  0.0  0.0  1.0

Nb Nb Al Cr
Nb Nb Al Cr 0 1 o o o 2 3 o o o 
Nb2CrAl is alpha Po structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Nb2CrAl clusters. Nb(1) is bonded in a 3-coordinate geometry to one Nb(1), one Cr(1), and one Al(1) atom. The Nb(1)-Nb(1) bond length is 0.90 Å. The Nb(1)-Cr(1) bond length is 1.17 Å. The Nb(1)-Al(1) bond length is 1.17 Å. Cr(1) is bonded in a distorted single-bond geometry to two equivalent Nb(1) and one Al(1) atom. The Cr(1)-Al(1) bond length is 0.90 Å. Al(1) is bonded in a distorted single-bond geometry to two equivalent Nb(1) and one Cr(1) atom.