The material described by Nb3AlN4 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to three equivalent N(1) and three equivalent N(2) atoms to form NbN6 octahedra that share corners with three equivalent Nb(2)N6 octahedra, corners with three equivalent Al(1)N6 octahedra, edges with three equivalent Nb(2)N6 octahedra, edges with three equivalent Al(1)N6 octahedra, and edges with six equivalent Nb(1)N6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the second Nb site, Nb(2) is bonded to six equivalent N(1) atoms to form a mixture of corner and edge-sharing NbN6 octahedra. The corner-sharing octahedra are not tilted. Al(1) is bonded to six equivalent N(2) atoms to form AlN6 octahedra that share corners with six equivalent Nb(1)N6 octahedra, edges with six equivalent Nb(1)N6 octahedra, and edges with six equivalent Al(1)N6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are two inequivalent N sites. In the first N site, N(1) is bonded to three equivalent Nb(1) and three equivalent Nb(2) atoms to form NNb6 octahedra that share corners with three equivalent N(2)Nb3Al3 octahedra, corners with three equivalent N(1)Nb6 octahedra, edges with three equivalent N(2)Nb3Al3 octahedra, and edges with nine equivalent N(1)Nb6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the second N site, N(2) is bonded to three equivalent Nb(1) and three equivalent Al(1) atoms to form NNb3Al3 octahedra that share corners with three equivalent N(2)Nb3Al3 octahedra, corners with three equivalent N(1)Nb6 octahedra, edges with three equivalent N(1)Nb6 octahedra, and edges with nine equivalent N(2)Nb3Al3 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. is represented by the CIF file [CIF]
data_Nb3AlN4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.772
_cell_length_b   10.772
_cell_length_c   10.772
_cell_angle_alpha   16.075
_cell_angle_beta   16.075
_cell_angle_gamma   16.075
_symmetry_Int_Tables_number   1
_cell_volume   83.552
_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  0.252  0.252  0.252  1.0
  Nb  Nb1  1  0.500  0.500  0.500  1.0
  Nb  Nb2  1  0.748  0.748  0.748  1.0
  Al  Al3  1  0.000  0.000  0.000  1.0
  N  N4  1  0.124  0.124  0.124  1.0
  N  N5  1  0.368  0.368  0.368  1.0
  N  N6  1  0.632  0.632  0.632  1.0
  N  N7  1  0.876  0.876  0.876  1.0
[/CIF]
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The material described by Nb3AlN4 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to three equivalent N(1) and three equivalent N(2) atoms to form NbN6 octahedra that share corners with three equivalent Nb(2)N6 octahedra, corners with three equivalent Al(1)N6 octahedra, edges with three equivalent Nb(2)N6 octahedra, edges with three equivalent Al(1)N6 octahedra, and edges with six equivalent Nb(1)N6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the second Nb site, Nb(2) is bonded to six equivalent N(1) atoms to form a mixture of corner and edge-sharing NbN6 octahedra. The corner-sharing octahedra are not tilted. Al(1) is bonded to six equivalent N(2) atoms to form AlN6 octahedra that share corners with six equivalent Nb(1)N6 octahedra, edges with six equivalent Nb(1)N6 octahedra, and edges with six equivalent Al(1)N6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are two inequivalent N sites. In the first N site, N(1) is bonded to three equivalent Nb(1) and three equivalent Nb(2) atoms to form NNb6 octahedra that share corners with three equivalent N(2)Nb3Al3 octahedra, corners with three equivalent N(1)Nb6 octahedra, edges with three equivalent N(2)Nb3Al3 octahedra, and edges with nine equivalent N(1)Nb6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the second N site, N(2) is bonded to three equivalent Nb(1) and three equivalent Al(1) atoms to form NNb3Al3 octahedra that share corners with three equivalent N(2)Nb3Al3 octahedra, corners with three equivalent N(1)Nb6 octahedra, edges with three equivalent N(1)Nb6 octahedra, and edges with nine equivalent N(2)Nb3Al3 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. is represented by the CIF file [CIF]
data_Nb3AlN4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.772
_cell_length_b   10.772
_cell_length_c   10.772
_cell_angle_alpha   16.075
_cell_angle_beta   16.075
_cell_angle_gamma   16.075
_symmetry_Int_Tables_number   1
_cell_volume   83.552
_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  0.252  0.252  0.252  1.0
  Nb  Nb1  1  0.500  0.500  0.500  1.0
  Nb  Nb2  1  0.748  0.748  0.748  1.0
  Al  Al3  1  0.000  0.000  0.000  1.0
  N  N4  1  0.124  0.124  0.124  1.0
  N  N5  1  0.368  0.368  0.368  1.0
  N  N6  1  0.632  0.632  0.632  1.0
  N  N7  1  0.876  0.876  0.876  1.0
[/CIF]
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