The structure described by Y3(Cr2Al7)4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 20-coordinate geometry to two equivalent Cr(1), four equivalent Cr(3), two equivalent Al(8), four equivalent Al(3), and eight equivalent Al(4) atoms. In the second Y site, Y(2) is bonded in a 20-coordinate geometry to one Cr(1), four equivalent Cr(2), one Al(7), one Al(8), one Al(9), two equivalent Al(1), two equivalent Al(2), four equivalent Al(5), and four equivalent Al(6) atoms. There are three inequivalent Cr sites. In the first Cr site, Cr(2) is bonded in a 12-coordinate geometry to two equivalent Y(2), two equivalent Cr(2), two equivalent Al(1), two equivalent Al(2), two equivalent Al(5), and two equivalent Al(6) atoms. In the second Cr site, Cr(3) is bonded in a 10-coordinate geometry to two equivalent Y(1), two equivalent Cr(3), four equivalent Al(3), and four equivalent Al(4) atoms. In the third Cr site, Cr(1) is bonded to one Y(1), one Y(2), two equivalent Al(1), two equivalent Al(3), two equivalent Al(4), two equivalent Al(6), and two equivalent Al(8) atoms to form distorted CrY2Al10 cuboctahedra that share  a cornercorner with one Al(7)Y2Al10 cuboctahedra,  a cornercorner with one Al(9)Y2Al10 cuboctahedra,  a cornercorner with one Al(8)Y2Al8Cr2 cuboctahedra, corners with three equivalent Cr(1)Y2Al10 cuboctahedra, and faces with two equivalent Al(8)Y2Al8Cr2 cuboctahedra. There are nine inequivalent Al sites. In the first Al site, Al(9) is bonded to two equivalent Y(2), two equivalent Al(7), four equivalent Al(2), and four equivalent Al(5) atoms to form AlY2Al10 cuboctahedra that share corners with two equivalent Cr(1)Y2Al10 cuboctahedra, corners with two equivalent Al(9)Y2Al10 cuboctahedra, corners with two equivalent Al(8)Y2Al8Cr2 cuboctahedra, and faces with two equivalent Al(7)Y2Al10 cuboctahedra. In the second Al site, Al(1) is bonded in a 10-coordinate geometry to one Y(2), one Cr(1), two equivalent Cr(2), one Al(3), one Al(4), one Al(8), and three equivalent Al(6) atoms. In the third Al site, Al(2) is bonded in a 12-coordinate geometry to one Y(2), two equivalent Cr(2), one Al(7), one Al(9), three equivalent Al(2), and four equivalent Al(5) atoms. In the fourth Al site, Al(3) is bonded in a 10-coordinate geometry to one Y(1), one Cr(1), two equivalent Cr(3), one Al(1), one Al(6), one Al(8), and three equivalent Al(4) atoms. In the fifth Al site, Al(4) is bonded in a 12-coordinate geometry to two equivalent Y(1), one Cr(1), two equivalent Cr(3), one Al(1), one Al(8), two equivalent Al(4), and three equivalent Al(3) atoms. In the sixth Al site, Al(5) is bonded in a 12-coordinate geometry to two equivalent Y(2), two equivalent Cr(2), one Al(5), one Al(6), one Al(7), one Al(9), and four equivalent Al(2) atoms. In the seventh Al site, Al(6) is bonded in a 12-coordinate geometry to two equivalent Y(2), one Cr(1), two equivalent Cr(2), one Al(3), one Al(5), one Al(6), one Al(8), and three equivalent Al(1) atoms. In the eighth Al site, Al(7) is bonded to two equivalent Y(2), two equivalent Al(9), four equivalent Al(2), and four equivalent Al(5) atoms to form AlY2Al10 cuboctahedra that share corners with two equivalent Cr(1)Y2Al10 cuboctahedra, corners with two equivalent Al(7)Y2Al10 cuboctahedra, corners with two equivalent Al(8)Y2Al8Cr2 cuboctahedra, and faces with two equivalent Al(9)Y2Al10 cuboctahedra. In the ninth Al site, Al(8) is bonded to one Y(1), one Y(2), two equivalent Cr(1), two equivalent Al(1), two equivalent Al(3), two equivalent Al(4), and two equivalent Al(6) atoms to form distorted AlY2Al8Cr2 cuboctahedra that share  a cornercorner with one Cr(1)Y2Al10 cuboctahedra,  a cornercorner with one Al(7)Y2Al10 cuboctahedra,  a cornercorner with one Al(9)Y2Al10 cuboctahedra, corners with three equivalent Al(8)Y2Al8Cr2 cuboctahedra, and faces with two equivalent Cr(1)Y2Al10 cuboctahedra. is represented by the CIF file [CIF]
data_Y3(Al7Cr2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.131
_cell_length_b   6.898
_cell_length_c   19.220
_cell_angle_alpha   87.032
_cell_angle_beta   98.001
_cell_angle_gamma   111.836
_symmetry_Int_Tables_number   1
_cell_volume   625.359
_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
  Y  Y0  1  0.333  0.000  0.667  1.0
  Y  Y1  1  0.001  0.000  0.000  1.0
  Y  Y2  1  0.666  0.000  0.333  1.0
  Al  Al3  1  0.127  0.349  0.889  1.0
  Al  Al4  1  0.793  0.366  0.222  1.0
  Al  Al5  1  0.461  0.349  0.556  1.0
  Al  Al6  1  0.205  0.651  0.778  1.0
  Al  Al7  1  0.874  0.634  0.111  1.0
  Al  Al8  1  0.539  0.651  0.444  1.0
  Al  Al9  1  0.554  0.349  0.778  1.0
  Al  Al10  1  0.240  0.366  0.111  1.0
  Al  Al11  1  0.888  0.349  0.444  1.0
  Al  Al12  1  0.779  0.651  0.889  1.0
  Al  Al13  1  0.427  0.634  0.222  1.0
  Al  Al14  1  0.112  0.651  0.556  1.0
  Al  Al15  1  0.767  0.773  0.738  1.0
  Al  Al16  1  0.419  0.773  0.069  1.0
  Al  Al17  1  0.101  0.773  0.406  1.0
  Al  Al18  1  0.565  0.227  0.927  1.0
  Al  Al19  1  0.247  0.227  0.264  1.0
  Al  Al20  1  0.900  0.227  0.595  1.0
  Al  Al21  1  0.338  0.773  0.927  1.0
  Al  Al22  1  0.020  0.773  0.264  1.0
  Al  Al23  1  0.673  0.773  0.595  1.0
  Al  Al24  1  0.993  0.227  0.738  1.0
  Al  Al25  1  0.646  0.227  0.069  1.0
  Al  Al26  1  0.328  0.227  0.406  1.0
  Al  Al27  1  0.333  0.000  0.167  1.0
  Al  Al28  1  0.000  0.000  0.500  1.0
  Al  Al29  1  0.666  0.000  0.833  1.0
  Al  Al30  1  0.833  0.000  0.167  1.0
  Cr  Cr31  1  0.500  0.000  0.499  1.0
  Cr  Cr32  1  0.166  0.000  0.834  1.0
  Cr  Cr33  1  0.997  0.493  1.000  1.0
  Cr  Cr34  1  0.669  0.507  0.334  1.0
  Cr  Cr35  1  0.333  0.500  0.667  1.0
  Cr  Cr36  1  0.504  0.507  1.000  1.0
  Cr  Cr37  1  0.162  0.493  0.334  1.0
  Cr  Cr38  1  0.833  0.500  0.667  1.0
[/CIF]
.
The structure described by Y3(Cr2Al7)4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 20-coordinate geometry to two equivalent Cr(1), four equivalent Cr(3), two equivalent Al(8), four equivalent Al(3), and eight equivalent Al(4) atoms. In the second Y site, Y(2) is bonded in a 20-coordinate geometry to one Cr(1), four equivalent Cr(2), one Al(7), one Al(8), one Al(9), two equivalent Al(1), two equivalent Al(2), four equivalent Al(5), and four equivalent Al(6) atoms. There are three inequivalent Cr sites. In the first Cr site, Cr(2) is bonded in a 12-coordinate geometry to two equivalent Y(2), two equivalent Cr(2), two equivalent Al(1), two equivalent Al(2), two equivalent Al(5), and two equivalent Al(6) atoms. In the second Cr site, Cr(3) is bonded in a 10-coordinate geometry to two equivalent Y(1), two equivalent Cr(3), four equivalent Al(3), and four equivalent Al(4) atoms. In the third Cr site, Cr(1) is bonded to one Y(1), one Y(2), two equivalent Al(1), two equivalent Al(3), two equivalent Al(4), two equivalent Al(6), and two equivalent Al(8) atoms to form distorted CrY2Al10 cuboctahedra that share  a cornercorner with one Al(7)Y2Al10 cuboctahedra,  a cornercorner with one Al(9)Y2Al10 cuboctahedra,  a cornercorner with one Al(8)Y2Al8Cr2 cuboctahedra, corners with three equivalent Cr(1)Y2Al10 cuboctahedra, and faces with two equivalent Al(8)Y2Al8Cr2 cuboctahedra. There are nine inequivalent Al sites. In the first Al site, Al(9) is bonded to two equivalent Y(2), two equivalent Al(7), four equivalent Al(2), and four equivalent Al(5) atoms to form AlY2Al10 cuboctahedra that share corners with two equivalent Cr(1)Y2Al10 cuboctahedra, corners with two equivalent Al(9)Y2Al10 cuboctahedra, corners with two equivalent Al(8)Y2Al8Cr2 cuboctahedra, and faces with two equivalent Al(7)Y2Al10 cuboctahedra. In the second Al site, Al(1) is bonded in a 10-coordinate geometry to one Y(2), one Cr(1), two equivalent Cr(2), one Al(3), one Al(4), one Al(8), and three equivalent Al(6) atoms. In the third Al site, Al(2) is bonded in a 12-coordinate geometry to one Y(2), two equivalent Cr(2), one Al(7), one Al(9), three equivalent Al(2), and four equivalent Al(5) atoms. In the fourth Al site, Al(3) is bonded in a 10-coordinate geometry to one Y(1), one Cr(1), two equivalent Cr(3), one Al(1), one Al(6), one Al(8), and three equivalent Al(4) atoms. In the fifth Al site, Al(4) is bonded in a 12-coordinate geometry to two equivalent Y(1), one Cr(1), two equivalent Cr(3), one Al(1), one Al(8), two equivalent Al(4), and three equivalent Al(3) atoms. In the sixth Al site, Al(5) is bonded in a 12-coordinate geometry to two equivalent Y(2), two equivalent Cr(2), one Al(5), one Al(6), one Al(7), one Al(9), and four equivalent Al(2) atoms. In the seventh Al site, Al(6) is bonded in a 12-coordinate geometry to two equivalent Y(2), one Cr(1), two equivalent Cr(2), one Al(3), one Al(5), one Al(6), one Al(8), and three equivalent Al(1) atoms. In the eighth Al site, Al(7) is bonded to two equivalent Y(2), two equivalent Al(9), four equivalent Al(2), and four equivalent Al(5) atoms to form AlY2Al10 cuboctahedra that share corners with two equivalent Cr(1)Y2Al10 cuboctahedra, corners with two equivalent Al(7)Y2Al10 cuboctahedra, corners with two equivalent Al(8)Y2Al8Cr2 cuboctahedra, and faces with two equivalent Al(9)Y2Al10 cuboctahedra. In the ninth Al site, Al(8) is bonded to one Y(1), one Y(2), two equivalent Cr(1), two equivalent Al(1), two equivalent Al(3), two equivalent Al(4), and two equivalent Al(6) atoms to form distorted AlY2Al8Cr2 cuboctahedra that share  a cornercorner with one Cr(1)Y2Al10 cuboctahedra,  a cornercorner with one Al(7)Y2Al10 cuboctahedra,  a cornercorner with one Al(9)Y2Al10 cuboctahedra, corners with three equivalent Al(8)Y2Al8Cr2 cuboctahedra, and faces with two equivalent Cr(1)Y2Al10 cuboctahedra. is represented by the CIF file [CIF]
data_Y3(Al7Cr2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.131
_cell_length_b   6.898
_cell_length_c   19.220
_cell_angle_alpha   87.032
_cell_angle_beta   98.001
_cell_angle_gamma   111.836
_symmetry_Int_Tables_number   1
_cell_volume   625.359
_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
  Y  Y0  1  0.333  0.000  0.667  1.0
  Y  Y1  1  0.001  0.000  0.000  1.0
  Y  Y2  1  0.666  0.000  0.333  1.0
  Al  Al3  1  0.127  0.349  0.889  1.0
  Al  Al4  1  0.793  0.366  0.222  1.0
  Al  Al5  1  0.461  0.349  0.556  1.0
  Al  Al6  1  0.205  0.651  0.778  1.0
  Al  Al7  1  0.874  0.634  0.111  1.0
  Al  Al8  1  0.539  0.651  0.444  1.0
  Al  Al9  1  0.554  0.349  0.778  1.0
  Al  Al10  1  0.240  0.366  0.111  1.0
  Al  Al11  1  0.888  0.349  0.444  1.0
  Al  Al12  1  0.779  0.651  0.889  1.0
  Al  Al13  1  0.427  0.634  0.222  1.0
  Al  Al14  1  0.112  0.651  0.556  1.0
  Al  Al15  1  0.767  0.773  0.738  1.0
  Al  Al16  1  0.419  0.773  0.069  1.0
  Al  Al17  1  0.101  0.773  0.406  1.0
  Al  Al18  1  0.565  0.227  0.927  1.0
  Al  Al19  1  0.247  0.227  0.264  1.0
  Al  Al20  1  0.900  0.227  0.595  1.0
  Al  Al21  1  0.338  0.773  0.927  1.0
  Al  Al22  1  0.020  0.773  0.264  1.0
  Al  Al23  1  0.673  0.773  0.595  1.0
  Al  Al24  1  0.993  0.227  0.738  1.0
  Al  Al25  1  0.646  0.227  0.069  1.0
  Al  Al26  1  0.328  0.227  0.406  1.0
  Al  Al27  1  0.333  0.000  0.167  1.0
  Al  Al28  1  0.000  0.000  0.500  1.0
  Al  Al29  1  0.666  0.000  0.833  1.0
  Al  Al30  1  0.833  0.000  0.167  1.0
  Cr  Cr31  1  0.500  0.000  0.499  1.0
  Cr  Cr32  1  0.166  0.000  0.834  1.0
  Cr  Cr33  1  0.997  0.493  1.000  1.0
  Cr  Cr34  1  0.669  0.507  0.334  1.0
  Cr  Cr35  1  0.333  0.500  0.667  1.0
  Cr  Cr36  1  0.504  0.507  1.000  1.0
  Cr  Cr37  1  0.162  0.493  0.334  1.0
  Cr  Cr38  1  0.833  0.500  0.667  1.0
[/CIF]
.