The structure described by Y5Al3C4 crystallizes in the tetragonal P4/mbm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 3-coordinate geometry to two equivalent Al(2), one C(1), and two equivalent C(2) atoms. In the second Y site, Y(2) is bonded to two equivalent C(2) and four equivalent C(1) atoms to form edge-sharing YC6 octahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a trigonal planar geometry to one C(2) and two equivalent C(1) atoms. In the second Al site, Al(2) is bonded in a body-centered cubic geometry to eight equivalent Y(1) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded to two equivalent Y(1), two equivalent Y(2), and two equivalent Al(1) atoms to form distorted CY4Al2 octahedra that share corners with two equivalent C(1)Y4Al2 octahedra, corners with two equivalent C(2)Y5Al octahedra, edges with three equivalent C(1)Y4Al2 octahedra, and edges with four equivalent C(2)Y5Al octahedra. The corner-sharing octahedral tilt angles range from 0-58°. In the second C site, C(2) is bonded to one Y(2), four equivalent Y(1), and one Al(1) atom to form CY5Al octahedra that share  a cornercorner with one C(2)Y5Al octahedra, corners with two equivalent C(1)Y4Al2 octahedra, edges with two equivalent C(2)Y5Al octahedra, and edges with four equivalent C(1)Y4Al2 octahedra. The corner-sharing octahedral tilt angles range from 0-58°. is represented by the CIF card [CIF]
data_Y5Al3C4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.919
_cell_length_b   10.919
_cell_length_c   3.524
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   420.093
_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
  Y  Y0  1  0.551  0.730  0.500  1.0
  Y  Y1  1  0.449  0.270  0.500  1.0
  Y  Y2  1  0.051  0.770  0.500  1.0
  Y  Y3  1  0.949  0.230  0.500  1.0
  Y  Y4  1  0.270  0.551  0.500  1.0
  Y  Y5  1  0.730  0.449  0.500  1.0
  Y  Y6  1  0.230  0.051  0.500  1.0
  Y  Y7  1  0.770  0.949  0.500  1.0
  Y  Y8  1  0.500  0.000  0.000  1.0
  Y  Y9  1  0.000  0.500  0.000  1.0
  Al  Al10  1  0.704  0.204  0.000  1.0
  Al  Al11  1  0.296  0.796  0.000  1.0
  Al  Al12  1  0.204  0.296  0.000  1.0
  Al  Al13  1  0.796  0.704  0.000  1.0
  Al  Al14  1  0.500  0.500  0.000  1.0
  Al  Al15  1  0.000  0.000  0.000  1.0
  C  C16  1  0.633  0.133  0.500  1.0
  C  C17  1  0.367  0.867  0.500  1.0
  C  C18  1  0.133  0.367  0.500  1.0
  C  C19  1  0.867  0.633  0.500  1.0
  C  C20  1  0.162  0.662  0.000  1.0
  C  C21  1  0.838  0.338  0.000  1.0
  C  C22  1  0.662  0.838  0.000  1.0
  C  C23  1  0.338  0.162  0.000  1.0
[/CIF]
.
The structure described by Y5Al3C4 crystallizes in the tetragonal P4/mbm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 3-coordinate geometry to two equivalent Al(2), one C(1), and two equivalent C(2) atoms. In the second Y site, Y(2) is bonded to two equivalent C(2) and four equivalent C(1) atoms to form edge-sharing YC6 octahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a trigonal planar geometry to one C(2) and two equivalent C(1) atoms. In the second Al site, Al(2) is bonded in a body-centered cubic geometry to eight equivalent Y(1) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded to two equivalent Y(1), two equivalent Y(2), and two equivalent Al(1) atoms to form distorted CY4Al2 octahedra that share corners with two equivalent C(1)Y4Al2 octahedra, corners with two equivalent C(2)Y5Al octahedra, edges with three equivalent C(1)Y4Al2 octahedra, and edges with four equivalent C(2)Y5Al octahedra. The corner-sharing octahedral tilt angles range from 0-58°. In the second C site, C(2) is bonded to one Y(2), four equivalent Y(1), and one Al(1) atom to form CY5Al octahedra that share  a cornercorner with one C(2)Y5Al octahedra, corners with two equivalent C(1)Y4Al2 octahedra, edges with two equivalent C(2)Y5Al octahedra, and edges with four equivalent C(1)Y4Al2 octahedra. The corner-sharing octahedral tilt angles range from 0-58°. is represented by the CIF card [CIF]
data_Y5Al3C4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.919
_cell_length_b   10.919
_cell_length_c   3.524
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   420.093
_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
  Y  Y0  1  0.551  0.730  0.500  1.0
  Y  Y1  1  0.449  0.270  0.500  1.0
  Y  Y2  1  0.051  0.770  0.500  1.0
  Y  Y3  1  0.949  0.230  0.500  1.0
  Y  Y4  1  0.270  0.551  0.500  1.0
  Y  Y5  1  0.730  0.449  0.500  1.0
  Y  Y6  1  0.230  0.051  0.500  1.0
  Y  Y7  1  0.770  0.949  0.500  1.0
  Y  Y8  1  0.500  0.000  0.000  1.0
  Y  Y9  1  0.000  0.500  0.000  1.0
  Al  Al10  1  0.704  0.204  0.000  1.0
  Al  Al11  1  0.296  0.796  0.000  1.0
  Al  Al12  1  0.204  0.296  0.000  1.0
  Al  Al13  1  0.796  0.704  0.000  1.0
  Al  Al14  1  0.500  0.500  0.000  1.0
  Al  Al15  1  0.000  0.000  0.000  1.0
  C  C16  1  0.633  0.133  0.500  1.0
  C  C17  1  0.367  0.867  0.500  1.0
  C  C18  1  0.133  0.367  0.500  1.0
  C  C19  1  0.867  0.633  0.500  1.0
  C  C20  1  0.162  0.662  0.000  1.0
  C  C21  1  0.838  0.338  0.000  1.0
  C  C22  1  0.662  0.838  0.000  1.0
  C  C23  1  0.338  0.162  0.000  1.0
[/CIF]
.