The crystal structure described by Nb4Al crystallizes in the orthorhombic Fmmm space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 8-coordinate geometry to two equivalent Nb(2), four equivalent Nb(1), and four equivalent Al(1) atoms. In the second Nb site, Nb(2) is bonded in a distorted body-centered cubic geometry to two equivalent Nb(1) and six equivalent Nb(2) atoms. Al(1) is bonded to eight equivalent Nb(1) and four equivalent Al(1) atoms to form a mixture of distorted face and corner-sharing AlNb8Al4 cuboctahedra. is represented by the CIF file [CIF]
data_Nb4Al
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.770
_cell_length_b   11.677
_cell_length_c   2.835
_cell_angle_alpha   84.917
_cell_angle_beta   81.201
_cell_angle_gamma   13.882
_symmetry_Int_Tables_number   1
_cell_volume   89.385
_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  Nb0  1  0.404  0.404  0.596  1.0
  Nb  Nb1  1  0.801  0.801  0.199  1.0
  Nb  Nb2  1  0.199  0.199  0.801  1.0
  Nb  Nb3  1  0.596  0.596  0.404  1.0
  Al  Al4  1  0.000  0.000  0.000  1.0
[/CIF]
.
The crystal structure described by Nb4Al crystallizes in the orthorhombic Fmmm space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 8-coordinate geometry to two equivalent Nb(2), four equivalent Nb(1), and four equivalent Al(1) atoms. In the second Nb site, Nb(2) is bonded in a distorted body-centered cubic geometry to two equivalent Nb(1) and six equivalent Nb(2) atoms. Al(1) is bonded to eight equivalent Nb(1) and four equivalent Al(1) atoms to form a mixture of distorted face and corner-sharing AlNb8Al4 cuboctahedra. is represented by the CIF file [CIF]
data_Nb4Al
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.770
_cell_length_b   11.677
_cell_length_c   2.835
_cell_angle_alpha   84.917
_cell_angle_beta   81.201
_cell_angle_gamma   13.882
_symmetry_Int_Tables_number   1
_cell_volume   89.385
_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  Nb0  1  0.404  0.404  0.596  1.0
  Nb  Nb1  1  0.801  0.801  0.199  1.0
  Nb  Nb2  1  0.199  0.199  0.801  1.0
  Nb  Nb3  1  0.596  0.596  0.404  1.0
  Al  Al4  1  0.000  0.000  0.000  1.0
[/CIF]
.