The compound described by Ti3AlC2 is MAX Phase-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two 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 to six equivalent C(1) atoms to form edge-sharing TiC6 octahedra. Al(1) is bonded to six equivalent Ti(1) and six equivalent Al(1) atoms to form distorted AlTi6Al6 cuboctahedra that share corners with six equivalent Al(1)Ti6Al6 cuboctahedra, corners with six equivalent C(1)Ti6 octahedra, edges with six equivalent Al(1)Ti6Al6 cuboctahedra, edges with six equivalent C(1)Ti6 octahedra, and faces with six equivalent Al(1)Ti6Al6 cuboctahedra. The corner-sharing octahedral tilt angles are 21°. C(1) is bonded to three equivalent Ti(1) and three equivalent Ti(2) atoms to form CTi6 octahedra that share corners with three equivalent Al(1)Ti6Al6 cuboctahedra, corners with three equivalent C(1)Ti6 octahedra, edges with three equivalent Al(1)Ti6Al6 cuboctahedra, and edges with nine equivalent C(1)Ti6 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_Ti3AlC2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.072
_cell_length_b   3.072
_cell_length_c   18.624
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   152.170
_cell_formula_units_Z   2
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  0.373  1.0
  Ti  Ti1  1  0.333  0.667  0.873  1.0
  Ti  Ti2  1  0.333  0.667  0.627  1.0
  Ti  Ti3  1  0.667  0.333  0.127  1.0
  Ti  Ti4  1  0.000  0.000  0.500  1.0
  Ti  Ti5  1  0.000  0.000  0.000  1.0
  Al  Al6  1  0.000  0.000  0.750  1.0
  Al  Al7  1  0.000  0.000  0.250  1.0
  C  C8  1  0.333  0.667  0.431  1.0
  C  C9  1  0.667  0.333  0.931  1.0
  C  C10  1  0.333  0.667  0.069  1.0
  C  C11  1  0.667  0.333  0.569  1.0
[/CIF]
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The compound described by Ti3AlC2 is MAX Phase-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two 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 to six equivalent C(1) atoms to form edge-sharing TiC6 octahedra. Al(1) is bonded to six equivalent Ti(1) and six equivalent Al(1) atoms to form distorted AlTi6Al6 cuboctahedra that share corners with six equivalent Al(1)Ti6Al6 cuboctahedra, corners with six equivalent C(1)Ti6 octahedra, edges with six equivalent Al(1)Ti6Al6 cuboctahedra, edges with six equivalent C(1)Ti6 octahedra, and faces with six equivalent Al(1)Ti6Al6 cuboctahedra. The corner-sharing octahedral tilt angles are 21°. C(1) is bonded to three equivalent Ti(1) and three equivalent Ti(2) atoms to form CTi6 octahedra that share corners with three equivalent Al(1)Ti6Al6 cuboctahedra, corners with three equivalent C(1)Ti6 octahedra, edges with three equivalent Al(1)Ti6Al6 cuboctahedra, and edges with nine equivalent C(1)Ti6 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_Ti3AlC2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.072
_cell_length_b   3.072
_cell_length_c   18.624
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   152.170
_cell_formula_units_Z   2
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  0.373  1.0
  Ti  Ti1  1  0.333  0.667  0.873  1.0
  Ti  Ti2  1  0.333  0.667  0.627  1.0
  Ti  Ti3  1  0.667  0.333  0.127  1.0
  Ti  Ti4  1  0.000  0.000  0.500  1.0
  Ti  Ti5  1  0.000  0.000  0.000  1.0
  Al  Al6  1  0.000  0.000  0.750  1.0
  Al  Al7  1  0.000  0.000  0.250  1.0
  C  C8  1  0.333  0.667  0.431  1.0
  C  C9  1  0.667  0.333  0.931  1.0
  C  C10  1  0.333  0.667  0.069  1.0
  C  C11  1  0.667  0.333  0.569  1.0
[/CIF]
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