The material described by Nb4SiC3 is MAX Phase structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to three equivalent C(1) and three equivalent C(2) atoms to form a mixture of edge and corner-sharing NbC6 octahedra. The corner-sharing octahedra are not tilted. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to three equivalent Si(1) and three equivalent C(2) atoms. Si(1) is bonded in a 6-coordinate geometry to six equivalent Nb(2) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded to six equivalent Nb(1) atoms to form a mixture of edge and corner-sharing CNb6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second C site, C(2) is bonded to three equivalent Nb(1) and three equivalent Nb(2) atoms to form a mixture of edge and corner-sharing CNb6 octahedra. The corner-sharing octahedral tilt angles are 1°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nb4SiC3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.206
_cell_length_b   3.206
_cell_length_c   23.005
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   204.779
_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
  Nb  Nb0  1  0.333  0.667  0.442  1.0
  Nb  Nb1  1  0.667  0.333  0.558  1.0
  Nb  Nb2  1  0.667  0.333  0.942  1.0
  Nb  Nb3  1  0.333  0.667  0.058  1.0
  Nb  Nb4  1  0.000  0.000  0.335  1.0
  Nb  Nb5  1  0.000  0.000  0.665  1.0
  Nb  Nb6  1  0.000  0.000  0.835  1.0
  Nb  Nb7  1  0.000  0.000  0.165  1.0
  Si  Si8  1  0.333  0.667  0.250  1.0
  Si  Si9  1  0.667  0.333  0.750  1.0
  C  C10  1  0.000  0.000  0.500  1.0
  C  C11  1  0.000  0.000  0.000  1.0
  C  C12  1  0.667  0.333  0.387  1.0
  C  C13  1  0.333  0.667  0.613  1.0
  C  C14  1  0.333  0.667  0.887  1.0
  C  C15  1  0.667  0.333  0.113  1.0
[/CIF]
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The material described by Nb4SiC3 is MAX Phase structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to three equivalent C(1) and three equivalent C(2) atoms to form a mixture of edge and corner-sharing NbC6 octahedra. The corner-sharing octahedra are not tilted. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to three equivalent Si(1) and three equivalent C(2) atoms. Si(1) is bonded in a 6-coordinate geometry to six equivalent Nb(2) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded to six equivalent Nb(1) atoms to form a mixture of edge and corner-sharing CNb6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second C site, C(2) is bonded to three equivalent Nb(1) and three equivalent Nb(2) atoms to form a mixture of edge and corner-sharing CNb6 octahedra. The corner-sharing octahedral tilt angles are 1°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nb4SiC3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.206
_cell_length_b   3.206
_cell_length_c   23.005
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   204.779
_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
  Nb  Nb0  1  0.333  0.667  0.442  1.0
  Nb  Nb1  1  0.667  0.333  0.558  1.0
  Nb  Nb2  1  0.667  0.333  0.942  1.0
  Nb  Nb3  1  0.333  0.667  0.058  1.0
  Nb  Nb4  1  0.000  0.000  0.335  1.0
  Nb  Nb5  1  0.000  0.000  0.665  1.0
  Nb  Nb6  1  0.000  0.000  0.835  1.0
  Nb  Nb7  1  0.000  0.000  0.165  1.0
  Si  Si8  1  0.333  0.667  0.250  1.0
  Si  Si9  1  0.667  0.333  0.750  1.0
  C  C10  1  0.000  0.000  0.500  1.0
  C  C11  1  0.000  0.000  0.000  1.0
  C  C12  1  0.667  0.333  0.387  1.0
  C  C13  1  0.333  0.667  0.613  1.0
  C  C14  1  0.333  0.667  0.887  1.0
  C  C15  1  0.667  0.333  0.113  1.0
[/CIF]
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