The crystal structure described by Ti8Al4CN3 is H-Phase-derived structured and crystallizes in the trigonal P-3m1 space group. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 3-coordinate geometry to three equivalent Al(1) and three equivalent C(1) atoms. In the second Ti site, Ti(2) is bonded in a 3-coordinate geometry to three equivalent Al(2) and three equivalent N(1) atoms. In the third Ti site, Ti(3) is bonded in a 3-coordinate geometry to three equivalent Al(1) and three equivalent N(2) atoms. In the fourth Ti site, Ti(4) is bonded in a 3-coordinate geometry to three equivalent Al(2) and three equivalent N(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to three equivalent Ti(1), three equivalent Ti(3), and six equivalent Al(1) atoms to form distorted AlTi6Al6 cuboctahedra that share corners with six equivalent Al(1)Ti6Al6 cuboctahedra, corners with three equivalent C(1)Ti6 octahedra, corners with three equivalent N(2)Ti6 octahedra, edges with six equivalent Al(1)Ti6Al6 cuboctahedra, edges with three equivalent C(1)Ti6 octahedra, edges with three equivalent N(2)Ti6 octahedra, and faces with six equivalent Al(1)Ti6Al6 cuboctahedra. The corner-sharing octahedral tilt angles are 19°. In the second Al site, Al(2) is bonded to three equivalent Ti(2), three equivalent Ti(4), and six equivalent Al(2) atoms to form distorted AlTi6Al6 cuboctahedra that share corners with six equivalent Al(2)Ti6Al6 cuboctahedra, corners with three equivalent N(1)Ti6 octahedra, corners with three equivalent N(2)Ti6 octahedra, edges with six equivalent Al(2)Ti6Al6 cuboctahedra, edges with three equivalent N(1)Ti6 octahedra, edges with three equivalent N(2)Ti6 octahedra, and faces with six equivalent Al(2)Ti6Al6 cuboctahedra. The corner-sharing octahedral tilt angles are 19°. C(1) is bonded to six equivalent Ti(1) atoms to form CTi6 octahedra that share corners with six equivalent Al(1)Ti6Al6 cuboctahedra, edges with six equivalent Al(1)Ti6Al6 cuboctahedra, and edges with six equivalent C(1)Ti6 octahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded to six equivalent Ti(2) atoms to form NTi6 octahedra that share corners with six equivalent Al(2)Ti6Al6 cuboctahedra, edges with six equivalent Al(2)Ti6Al6 cuboctahedra, and edges with six equivalent N(1)Ti6 octahedra. In the second N site, N(2) is bonded to three equivalent Ti(3) and three equivalent Ti(4) atoms to form NTi6 octahedra that share corners with three equivalent Al(1)Ti6Al6 cuboctahedra, corners with three equivalent Al(2)Ti6Al6 cuboctahedra, edges with three equivalent Al(1)Ti6Al6 cuboctahedra, edges with three equivalent Al(2)Ti6Al6 cuboctahedra, and edges with six equivalent N(2)Ti6 octahedra. is represented by the CIF file [CIF]
data_Ti8Al4CN3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.017
_cell_length_b   3.017
_cell_length_c   27.312
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   215.298
_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
  Ti  Ti0  1  0.667  0.333  0.457  1.0
  Ti  Ti1  1  0.667  0.333  0.958  1.0
  Ti  Ti2  1  0.333  0.667  0.543  1.0
  Ti  Ti3  1  0.333  0.667  0.042  1.0
  Ti  Ti4  1  0.333  0.667  0.708  1.0
  Ti  Ti5  1  0.333  0.667  0.207  1.0
  Ti  Ti6  1  0.667  0.333  0.292  1.0
  Ti  Ti7  1  0.667  0.333  0.793  1.0
  Al  Al8  1  0.667  0.333  0.626  1.0
  Al  Al9  1  0.667  0.333  0.125  1.0
  Al  Al10  1  0.333  0.667  0.374  1.0
  Al  Al11  1  0.333  0.667  0.875  1.0
  C  C12  1  0.000  0.000  0.500  1.0
  N  N13  1  0.000  0.000  0.000  1.0
  N  N14  1  0.000  0.000  0.750  1.0
  N  N15  1  0.000  0.000  0.250  1.0
[/CIF]
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The crystal structure described by Ti8Al4CN3 is H-Phase-derived structured and crystallizes in the trigonal P-3m1 space group. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 3-coordinate geometry to three equivalent Al(1) and three equivalent C(1) atoms. In the second Ti site, Ti(2) is bonded in a 3-coordinate geometry to three equivalent Al(2) and three equivalent N(1) atoms. In the third Ti site, Ti(3) is bonded in a 3-coordinate geometry to three equivalent Al(1) and three equivalent N(2) atoms. In the fourth Ti site, Ti(4) is bonded in a 3-coordinate geometry to three equivalent Al(2) and three equivalent N(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to three equivalent Ti(1), three equivalent Ti(3), and six equivalent Al(1) atoms to form distorted AlTi6Al6 cuboctahedra that share corners with six equivalent Al(1)Ti6Al6 cuboctahedra, corners with three equivalent C(1)Ti6 octahedra, corners with three equivalent N(2)Ti6 octahedra, edges with six equivalent Al(1)Ti6Al6 cuboctahedra, edges with three equivalent C(1)Ti6 octahedra, edges with three equivalent N(2)Ti6 octahedra, and faces with six equivalent Al(1)Ti6Al6 cuboctahedra. The corner-sharing octahedral tilt angles are 19°. In the second Al site, Al(2) is bonded to three equivalent Ti(2), three equivalent Ti(4), and six equivalent Al(2) atoms to form distorted AlTi6Al6 cuboctahedra that share corners with six equivalent Al(2)Ti6Al6 cuboctahedra, corners with three equivalent N(1)Ti6 octahedra, corners with three equivalent N(2)Ti6 octahedra, edges with six equivalent Al(2)Ti6Al6 cuboctahedra, edges with three equivalent N(1)Ti6 octahedra, edges with three equivalent N(2)Ti6 octahedra, and faces with six equivalent Al(2)Ti6Al6 cuboctahedra. The corner-sharing octahedral tilt angles are 19°. C(1) is bonded to six equivalent Ti(1) atoms to form CTi6 octahedra that share corners with six equivalent Al(1)Ti6Al6 cuboctahedra, edges with six equivalent Al(1)Ti6Al6 cuboctahedra, and edges with six equivalent C(1)Ti6 octahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded to six equivalent Ti(2) atoms to form NTi6 octahedra that share corners with six equivalent Al(2)Ti6Al6 cuboctahedra, edges with six equivalent Al(2)Ti6Al6 cuboctahedra, and edges with six equivalent N(1)Ti6 octahedra. In the second N site, N(2) is bonded to three equivalent Ti(3) and three equivalent Ti(4) atoms to form NTi6 octahedra that share corners with three equivalent Al(1)Ti6Al6 cuboctahedra, corners with three equivalent Al(2)Ti6Al6 cuboctahedra, edges with three equivalent Al(1)Ti6Al6 cuboctahedra, edges with three equivalent Al(2)Ti6Al6 cuboctahedra, and edges with six equivalent N(2)Ti6 octahedra. is represented by the CIF file [CIF]
data_Ti8Al4CN3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.017
_cell_length_b   3.017
_cell_length_c   27.312
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   215.298
_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
  Ti  Ti0  1  0.667  0.333  0.457  1.0
  Ti  Ti1  1  0.667  0.333  0.958  1.0
  Ti  Ti2  1  0.333  0.667  0.543  1.0
  Ti  Ti3  1  0.333  0.667  0.042  1.0
  Ti  Ti4  1  0.333  0.667  0.708  1.0
  Ti  Ti5  1  0.333  0.667  0.207  1.0
  Ti  Ti6  1  0.667  0.333  0.292  1.0
  Ti  Ti7  1  0.667  0.333  0.793  1.0
  Al  Al8  1  0.667  0.333  0.626  1.0
  Al  Al9  1  0.667  0.333  0.125  1.0
  Al  Al10  1  0.333  0.667  0.374  1.0
  Al  Al11  1  0.333  0.667  0.875  1.0
  C  C12  1  0.000  0.000  0.500  1.0
  N  N13  1  0.000  0.000  0.000  1.0
  N  N14  1  0.000  0.000  0.750  1.0
  N  N15  1  0.000  0.000  0.250  1.0
[/CIF]
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