The structure described by TaNbAl6 is beta Cu3Ti-derived structured and crystallizes in the tetragonal P4/mmm space group. Ta(1) is bonded to four equivalent Al(2) and eight equivalent Al(3) atoms to form TaAl12 cuboctahedra that share corners with four equivalent Ta(1)Al12 cuboctahedra, corners with eight equivalent Al(1)Nb4Al8 cuboctahedra, edges with eight equivalent Nb(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Ta2Nb2Al8 cuboctahedra, faces with two equivalent Al(1)Nb4Al8 cuboctahedra, faces with four equivalent Ta(1)Al12 cuboctahedra, faces with four equivalent Al(2)Ta4Al8 cuboctahedra, and faces with eight equivalent Al(3)Ta2Nb2Al8 cuboctahedra. Nb(1) is bonded to four equivalent Al(1) and eight equivalent Al(3) atoms to form NbAl12 cuboctahedra that share corners with four equivalent Nb(1)Al12 cuboctahedra, corners with eight equivalent Al(2)Ta4Al8 cuboctahedra, edges with eight equivalent Ta(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Ta2Nb2Al8 cuboctahedra, faces with two equivalent Al(2)Ta4Al8 cuboctahedra, faces with four equivalent Nb(1)Al12 cuboctahedra, faces with four equivalent Al(1)Nb4Al8 cuboctahedra, and faces with eight equivalent Al(3)Ta2Nb2Al8 cuboctahedra. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Nb(1) and eight equivalent Al(3) atoms to form AlNb4Al8 cuboctahedra that share corners with four equivalent Al(1)Nb4Al8 cuboctahedra, corners with eight equivalent Ta(1)Al12 cuboctahedra, edges with eight equivalent Al(2)Ta4Al8 cuboctahedra, edges with sixteen equivalent Al(3)Ta2Nb2Al8 cuboctahedra, faces with two equivalent Ta(1)Al12 cuboctahedra, faces with four equivalent Nb(1)Al12 cuboctahedra, faces with four equivalent Al(1)Nb4Al8 cuboctahedra, and faces with eight equivalent Al(3)Ta2Nb2Al8 cuboctahedra. In the second Al site, Al(2) is bonded to four equivalent Ta(1) and eight equivalent Al(3) atoms to form distorted AlTa4Al8 cuboctahedra that share corners with four equivalent Al(2)Ta4Al8 cuboctahedra, corners with eight equivalent Nb(1)Al12 cuboctahedra, edges with eight equivalent Al(1)Nb4Al8 cuboctahedra, edges with sixteen equivalent Al(3)Ta2Nb2Al8 cuboctahedra, faces with two equivalent Nb(1)Al12 cuboctahedra, faces with four equivalent Ta(1)Al12 cuboctahedra, faces with four equivalent Al(2)Ta4Al8 cuboctahedra, and faces with eight equivalent Al(3)Ta2Nb2Al8 cuboctahedra. In the third Al site, Al(3) is bonded to two equivalent Ta(1), two equivalent Nb(1), two equivalent Al(1), two equivalent Al(2), and four equivalent Al(3) atoms to form AlTa2Nb2Al8 cuboctahedra that share corners with twelve equivalent Al(3)Ta2Nb2Al8 cuboctahedra, edges with four equivalent Ta(1)Al12 cuboctahedra, edges with four equivalent Nb(1)Al12 cuboctahedra, edges with four equivalent Al(1)Nb4Al8 cuboctahedra, edges with four equivalent Al(2)Ta4Al8 cuboctahedra, edges with eight equivalent Al(3)Ta2Nb2Al8 cuboctahedra, faces with two equivalent Ta(1)Al12 cuboctahedra, faces with two equivalent Nb(1)Al12 cuboctahedra, faces with two equivalent Al(1)Nb4Al8 cuboctahedra, faces with two equivalent Al(2)Ta4Al8 cuboctahedra, and faces with ten equivalent Al(3)Ta2Nb2Al8 cuboctahedra. is represented by the CIF card [CIF]
data_TaNbAl6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.834
_cell_length_b   3.834
_cell_length_c   8.536
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   125.452
_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
  Ta  Ta0  1  0.500  0.500  0.500  1.0
  Nb  Nb1  1  0.000  0.000  0.000  1.0
  Al  Al2  1  0.500  0.500  0.000  1.0
  Al  Al3  1  0.000  0.000  0.500  1.0
  Al  Al4  1  0.000  0.500  0.251  1.0
  Al  Al5  1  0.500  0.000  0.749  1.0
  Al  Al6  1  0.500  0.000  0.251  1.0
  Al  Al7  1  0.000  0.500  0.749  1.0
[/CIF]
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The structure described by TaNbAl6 is beta Cu3Ti-derived structured and crystallizes in the tetragonal P4/mmm space group. Ta(1) is bonded to four equivalent Al(2) and eight equivalent Al(3) atoms to form TaAl12 cuboctahedra that share corners with four equivalent Ta(1)Al12 cuboctahedra, corners with eight equivalent Al(1)Nb4Al8 cuboctahedra, edges with eight equivalent Nb(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Ta2Nb2Al8 cuboctahedra, faces with two equivalent Al(1)Nb4Al8 cuboctahedra, faces with four equivalent Ta(1)Al12 cuboctahedra, faces with four equivalent Al(2)Ta4Al8 cuboctahedra, and faces with eight equivalent Al(3)Ta2Nb2Al8 cuboctahedra. Nb(1) is bonded to four equivalent Al(1) and eight equivalent Al(3) atoms to form NbAl12 cuboctahedra that share corners with four equivalent Nb(1)Al12 cuboctahedra, corners with eight equivalent Al(2)Ta4Al8 cuboctahedra, edges with eight equivalent Ta(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Ta2Nb2Al8 cuboctahedra, faces with two equivalent Al(2)Ta4Al8 cuboctahedra, faces with four equivalent Nb(1)Al12 cuboctahedra, faces with four equivalent Al(1)Nb4Al8 cuboctahedra, and faces with eight equivalent Al(3)Ta2Nb2Al8 cuboctahedra. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Nb(1) and eight equivalent Al(3) atoms to form AlNb4Al8 cuboctahedra that share corners with four equivalent Al(1)Nb4Al8 cuboctahedra, corners with eight equivalent Ta(1)Al12 cuboctahedra, edges with eight equivalent Al(2)Ta4Al8 cuboctahedra, edges with sixteen equivalent Al(3)Ta2Nb2Al8 cuboctahedra, faces with two equivalent Ta(1)Al12 cuboctahedra, faces with four equivalent Nb(1)Al12 cuboctahedra, faces with four equivalent Al(1)Nb4Al8 cuboctahedra, and faces with eight equivalent Al(3)Ta2Nb2Al8 cuboctahedra. In the second Al site, Al(2) is bonded to four equivalent Ta(1) and eight equivalent Al(3) atoms to form distorted AlTa4Al8 cuboctahedra that share corners with four equivalent Al(2)Ta4Al8 cuboctahedra, corners with eight equivalent Nb(1)Al12 cuboctahedra, edges with eight equivalent Al(1)Nb4Al8 cuboctahedra, edges with sixteen equivalent Al(3)Ta2Nb2Al8 cuboctahedra, faces with two equivalent Nb(1)Al12 cuboctahedra, faces with four equivalent Ta(1)Al12 cuboctahedra, faces with four equivalent Al(2)Ta4Al8 cuboctahedra, and faces with eight equivalent Al(3)Ta2Nb2Al8 cuboctahedra. In the third Al site, Al(3) is bonded to two equivalent Ta(1), two equivalent Nb(1), two equivalent Al(1), two equivalent Al(2), and four equivalent Al(3) atoms to form AlTa2Nb2Al8 cuboctahedra that share corners with twelve equivalent Al(3)Ta2Nb2Al8 cuboctahedra, edges with four equivalent Ta(1)Al12 cuboctahedra, edges with four equivalent Nb(1)Al12 cuboctahedra, edges with four equivalent Al(1)Nb4Al8 cuboctahedra, edges with four equivalent Al(2)Ta4Al8 cuboctahedra, edges with eight equivalent Al(3)Ta2Nb2Al8 cuboctahedra, faces with two equivalent Ta(1)Al12 cuboctahedra, faces with two equivalent Nb(1)Al12 cuboctahedra, faces with two equivalent Al(1)Nb4Al8 cuboctahedra, faces with two equivalent Al(2)Ta4Al8 cuboctahedra, and faces with ten equivalent Al(3)Ta2Nb2Al8 cuboctahedra. is represented by the CIF card [CIF]
data_TaNbAl6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.834
_cell_length_b   3.834
_cell_length_c   8.536
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   125.452
_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
  Ta  Ta0  1  0.500  0.500  0.500  1.0
  Nb  Nb1  1  0.000  0.000  0.000  1.0
  Al  Al2  1  0.500  0.500  0.000  1.0
  Al  Al3  1  0.000  0.000  0.500  1.0
  Al  Al4  1  0.000  0.500  0.251  1.0
  Al  Al5  1  0.500  0.000  0.749  1.0
  Al  Al6  1  0.500  0.000  0.251  1.0
  Al  Al7  1  0.000  0.500  0.749  1.0
[/CIF]
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