The compound described by Ti2Ta2NbC5 is alpha Po-derived structured and crystallizes in the trigonal R3m space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to three equivalent C(1) and three equivalent C(3) atoms to form TiC6 octahedra that share corners with three equivalent Ti(2)C6 octahedra, corners with three equivalent Ta(2)C6 octahedra, edges with three equivalent Ti(2)C6 octahedra, edges with three equivalent Ta(2)C6 octahedra, and edges with six equivalent Ti(1)C6 octahedra. The corner-sharing octahedra are not tilted. In the second Ti site, Ti(2) is bonded to three equivalent C(1) and three equivalent C(4) atoms to form TiC6 octahedra that share corners with three equivalent Ti(1)C6 octahedra, corners with three equivalent Nb(1)C6 octahedra, edges with three equivalent Ti(1)C6 octahedra, edges with three equivalent Nb(1)C6 octahedra, and edges with six equivalent Ti(2)C6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to three equivalent C(2) and three equivalent C(5) atoms to form TaC6 octahedra that share corners with three equivalent Ta(2)C6 octahedra, corners with three equivalent Nb(1)C6 octahedra, edges with three equivalent Ta(2)C6 octahedra, edges with three equivalent Nb(1)C6 octahedra, and edges with six equivalent Ta(1)C6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Ta site, Ta(2) is bonded to three equivalent C(2) and three equivalent C(3) atoms to form TaC6 octahedra that share corners with three equivalent Ti(1)C6 octahedra, corners with three equivalent Ta(1)C6 octahedra, edges with three equivalent Ti(1)C6 octahedra, edges with three equivalent Ta(1)C6 octahedra, and edges with six equivalent Ta(2)C6 octahedra. The corner-sharing octahedra are not tilted. Nb(1) is bonded to three equivalent C(4) and three equivalent C(5) atoms to form NbC6 octahedra that share corners with three equivalent Ti(2)C6 octahedra, corners with three equivalent Ta(1)C6 octahedra, edges with three equivalent Ti(2)C6 octahedra, edges with three equivalent Ta(1)C6 octahedra, and edges with six equivalent Nb(1)C6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are five inequivalent C sites. In the first C site, 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 C(3)Ta3Ti3 octahedra, corners with three equivalent C(4)Ti3Nb3 octahedra, edges with three equivalent C(3)Ta3Ti3 octahedra, edges with three equivalent C(4)Ti3Nb3 octahedra, and edges with six equivalent C(1)Ti6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second C site, C(2) is bonded to three equivalent Ta(1) and three equivalent Ta(2) atoms to form CTa6 octahedra that share corners with three equivalent C(5)Ta3Nb3 octahedra, corners with three equivalent C(3)Ta3Ti3 octahedra, edges with three equivalent C(5)Ta3Nb3 octahedra, edges with three equivalent C(3)Ta3Ti3 octahedra, and edges with six equivalent C(2)Ta6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the third C site, C(3) is bonded to three equivalent Ti(1) and three equivalent Ta(2) atoms to form CTa3Ti3 octahedra that share corners with three equivalent C(2)Ta6 octahedra, corners with three equivalent C(1)Ti6 octahedra, edges with three equivalent C(2)Ta6 octahedra, edges with three equivalent C(1)Ti6 octahedra, and edges with six equivalent C(3)Ta3Ti3 octahedra. The corner-sharing octahedral tilt angles are 1°. In the fourth C site, C(4) is bonded to three equivalent Ti(2) and three equivalent Nb(1) atoms to form CTi3Nb3 octahedra that share corners with three equivalent C(5)Ta3Nb3 octahedra, corners with three equivalent C(1)Ti6 octahedra, edges with three equivalent C(5)Ta3Nb3 octahedra, edges with three equivalent C(1)Ti6 octahedra, and edges with six equivalent C(4)Ti3Nb3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the fifth C site, C(5) is bonded to three equivalent Ta(1) and three equivalent Nb(1) atoms to form CTa3Nb3 octahedra that share corners with three equivalent C(2)Ta6 octahedra, corners with three equivalent C(4)Ti3Nb3 octahedra, edges with three equivalent C(2)Ta6 octahedra, edges with three equivalent C(4)Ti3Nb3 octahedra, and edges with six equivalent C(5)Ta3Nb3 octahedra. The corner-sharing octahedral tilt angles are 1°. is represented by the CIF file [CIF]
data_Ta2Ti2NbC5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.883
_cell_length_b   12.883
_cell_length_c   12.883
_cell_angle_alpha   13.995
_cell_angle_beta   13.995
_cell_angle_gamma   13.995
_symmetry_Int_Tables_number   1
_cell_volume   108.843
_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  0.900  0.900  0.900  1.0
  Ta  Ta1  1  0.498  0.498  0.498  1.0
  Ti  Ti2  1  0.099  0.099  0.099  1.0
  Ti  Ti3  1  0.701  0.701  0.701  1.0
  Nb  Nb4  1  0.302  0.302  0.302  1.0
  C  C5  1  0.400  0.400  0.400  1.0
  C  C6  1  0.199  0.199  0.199  1.0
  C  C7  1  0.799  0.799  0.799  1.0
  C  C8  1  0.002  0.002  0.002  1.0
  C  C9  1  0.600  0.600  0.600  1.0
[/CIF]
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The compound described by Ti2Ta2NbC5 is alpha Po-derived structured and crystallizes in the trigonal R3m space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to three equivalent C(1) and three equivalent C(3) atoms to form TiC6 octahedra that share corners with three equivalent Ti(2)C6 octahedra, corners with three equivalent Ta(2)C6 octahedra, edges with three equivalent Ti(2)C6 octahedra, edges with three equivalent Ta(2)C6 octahedra, and edges with six equivalent Ti(1)C6 octahedra. The corner-sharing octahedra are not tilted. In the second Ti site, Ti(2) is bonded to three equivalent C(1) and three equivalent C(4) atoms to form TiC6 octahedra that share corners with three equivalent Ti(1)C6 octahedra, corners with three equivalent Nb(1)C6 octahedra, edges with three equivalent Ti(1)C6 octahedra, edges with three equivalent Nb(1)C6 octahedra, and edges with six equivalent Ti(2)C6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to three equivalent C(2) and three equivalent C(5) atoms to form TaC6 octahedra that share corners with three equivalent Ta(2)C6 octahedra, corners with three equivalent Nb(1)C6 octahedra, edges with three equivalent Ta(2)C6 octahedra, edges with three equivalent Nb(1)C6 octahedra, and edges with six equivalent Ta(1)C6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Ta site, Ta(2) is bonded to three equivalent C(2) and three equivalent C(3) atoms to form TaC6 octahedra that share corners with three equivalent Ti(1)C6 octahedra, corners with three equivalent Ta(1)C6 octahedra, edges with three equivalent Ti(1)C6 octahedra, edges with three equivalent Ta(1)C6 octahedra, and edges with six equivalent Ta(2)C6 octahedra. The corner-sharing octahedra are not tilted. Nb(1) is bonded to three equivalent C(4) and three equivalent C(5) atoms to form NbC6 octahedra that share corners with three equivalent Ti(2)C6 octahedra, corners with three equivalent Ta(1)C6 octahedra, edges with three equivalent Ti(2)C6 octahedra, edges with three equivalent Ta(1)C6 octahedra, and edges with six equivalent Nb(1)C6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are five inequivalent C sites. In the first C site, 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 C(3)Ta3Ti3 octahedra, corners with three equivalent C(4)Ti3Nb3 octahedra, edges with three equivalent C(3)Ta3Ti3 octahedra, edges with three equivalent C(4)Ti3Nb3 octahedra, and edges with six equivalent C(1)Ti6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second C site, C(2) is bonded to three equivalent Ta(1) and three equivalent Ta(2) atoms to form CTa6 octahedra that share corners with three equivalent C(5)Ta3Nb3 octahedra, corners with three equivalent C(3)Ta3Ti3 octahedra, edges with three equivalent C(5)Ta3Nb3 octahedra, edges with three equivalent C(3)Ta3Ti3 octahedra, and edges with six equivalent C(2)Ta6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the third C site, C(3) is bonded to three equivalent Ti(1) and three equivalent Ta(2) atoms to form CTa3Ti3 octahedra that share corners with three equivalent C(2)Ta6 octahedra, corners with three equivalent C(1)Ti6 octahedra, edges with three equivalent C(2)Ta6 octahedra, edges with three equivalent C(1)Ti6 octahedra, and edges with six equivalent C(3)Ta3Ti3 octahedra. The corner-sharing octahedral tilt angles are 1°. In the fourth C site, C(4) is bonded to three equivalent Ti(2) and three equivalent Nb(1) atoms to form CTi3Nb3 octahedra that share corners with three equivalent C(5)Ta3Nb3 octahedra, corners with three equivalent C(1)Ti6 octahedra, edges with three equivalent C(5)Ta3Nb3 octahedra, edges with three equivalent C(1)Ti6 octahedra, and edges with six equivalent C(4)Ti3Nb3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the fifth C site, C(5) is bonded to three equivalent Ta(1) and three equivalent Nb(1) atoms to form CTa3Nb3 octahedra that share corners with three equivalent C(2)Ta6 octahedra, corners with three equivalent C(4)Ti3Nb3 octahedra, edges with three equivalent C(2)Ta6 octahedra, edges with three equivalent C(4)Ti3Nb3 octahedra, and edges with six equivalent C(5)Ta3Nb3 octahedra. The corner-sharing octahedral tilt angles are 1°. is represented by the CIF file [CIF]
data_Ta2Ti2NbC5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.883
_cell_length_b   12.883
_cell_length_c   12.883
_cell_angle_alpha   13.995
_cell_angle_beta   13.995
_cell_angle_gamma   13.995
_symmetry_Int_Tables_number   1
_cell_volume   108.843
_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  0.900  0.900  0.900  1.0
  Ta  Ta1  1  0.498  0.498  0.498  1.0
  Ti  Ti2  1  0.099  0.099  0.099  1.0
  Ti  Ti3  1  0.701  0.701  0.701  1.0
  Nb  Nb4  1  0.302  0.302  0.302  1.0
  C  C5  1  0.400  0.400  0.400  1.0
  C  C6  1  0.199  0.199  0.199  1.0
  C  C7  1  0.799  0.799  0.799  1.0
  C  C8  1  0.002  0.002  0.002  1.0
  C  C9  1  0.600  0.600  0.600  1.0
[/CIF]
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