The compound described by ErGdAl6 crystallizes in the trigonal R3m space group. There are three inequivalent Er sites. In the first Er site, Er(1) is bonded to three equivalent Al(2), three equivalent Al(3), and six equivalent Al(5) atoms to form ErAl12 cuboctahedra that share corners with six equivalent Er(1)Al12 cuboctahedra,  a faceface with one Gd(1)Al12 cuboctahedra,  a faceface with one Gd(2)Al12 cuboctahedra, faces with three equivalent Er(3)Al12 cuboctahedra, and faces with three equivalent Gd(3)Al12 cuboctahedra. In the second Er site, Er(2) is bonded to three equivalent Al(1), three equivalent Al(4), and six equivalent Al(6) atoms to form ErAl12 cuboctahedra that share corners with six equivalent Er(2)Al12 cuboctahedra,  a faceface with one Er(3)Al12 cuboctahedra,  a faceface with one Gd(3)Al12 cuboctahedra, faces with three equivalent Gd(1)Al12 cuboctahedra, and faces with three equivalent Gd(2)Al12 cuboctahedra. In the third Er site, Er(3) is bonded to three equivalent Al(1), three equivalent Al(5), and six equivalent Al(3) atoms to form ErAl12 cuboctahedra that share corners with three equivalent Gd(3)Al12 cuboctahedra, corners with six equivalent Er(3)Al12 cuboctahedra,  a faceface with one Er(2)Al12 cuboctahedra, faces with three equivalent Er(1)Al12 cuboctahedra, and faces with three equivalent Gd(2)Al12 cuboctahedra. There are three inequivalent Gd sites. In the first Gd site, Gd(1) is bonded to three equivalent Al(2), three equivalent Al(6), and six equivalent Al(4) atoms to form GdAl12 cuboctahedra that share corners with three equivalent Gd(2)Al12 cuboctahedra, corners with six equivalent Gd(1)Al12 cuboctahedra,  a faceface with one Er(1)Al12 cuboctahedra, faces with three equivalent Er(2)Al12 cuboctahedra, and faces with three equivalent Gd(3)Al12 cuboctahedra. In the second Gd site, Gd(2) is bonded to three equivalent Al(3), three equivalent Al(6), and six equivalent Al(1) atoms to form GdAl12 cuboctahedra that share corners with three equivalent Gd(1)Al12 cuboctahedra, corners with six equivalent Gd(2)Al12 cuboctahedra,  a faceface with one Er(1)Al12 cuboctahedra, faces with three equivalent Er(2)Al12 cuboctahedra, and faces with three equivalent Er(3)Al12 cuboctahedra. In the third Gd site, Gd(3) is bonded to three equivalent Al(4), three equivalent Al(5), and six equivalent Al(2) atoms to form GdAl12 cuboctahedra that share corners with three equivalent Er(3)Al12 cuboctahedra, corners with six equivalent Gd(3)Al12 cuboctahedra,  a faceface with one Er(2)Al12 cuboctahedra, faces with three equivalent Er(1)Al12 cuboctahedra, and faces with three equivalent Gd(1)Al12 cuboctahedra. There are six inequivalent Al sites. In the first Al site, Al(1) is bonded in a 10-coordinate geometry to one Er(2), one Er(3), two equivalent Gd(2), two equivalent Al(1), two equivalent Al(3), and two equivalent Al(6) atoms. In the second Al site, Al(2) is bonded in a 10-coordinate geometry to one Er(1), one Gd(1), two equivalent Gd(3), two equivalent Al(2), two equivalent Al(4), and two equivalent Al(5) atoms. In the third Al site, Al(3) is bonded in a 10-coordinate geometry to one Er(1), two equivalent Er(3), one Gd(2), two equivalent Al(1), two equivalent Al(3), and two equivalent Al(5) atoms. In the fourth Al site, Al(4) is bonded in a 10-coordinate geometry to one Er(2), one Gd(3), two equivalent Gd(1), two equivalent Al(2), two equivalent Al(4), and two equivalent Al(6) atoms. In the fifth Al site, Al(5) is bonded in a 12-coordinate geometry to one Er(3), two equivalent Er(1), one Gd(3), two equivalent Al(2), two equivalent Al(3), and four equivalent Al(5) atoms. In the sixth Al site, Al(6) is bonded in a 12-coordinate geometry to two equivalent Er(2), one Gd(1), one Gd(2), two equivalent Al(1), two equivalent Al(4), and four equivalent Al(6) atoms. is represented by the CIF file [CIF]
data_GdErAl6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.579
_cell_length_b   14.579
_cell_length_c   14.579
_cell_angle_alpha   24.544
_cell_angle_beta   24.544
_cell_angle_gamma   24.544
_symmetry_Int_Tables_number   1
_cell_volume   470.094
_cell_formula_units_Z   3
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
  Gd  Gd0  1  0.111  0.111  0.111  1.0
  Gd  Gd1  1  0.892  0.892  0.892  1.0
  Gd  Gd2  1  0.392  0.392  0.392  1.0
  Er  Er3  1  0.001  0.001  0.001  1.0
  Er  Er4  1  0.501  0.501  0.501  1.0
  Er  Er5  1  0.611  0.611  0.611  1.0
  Al  Al6  1  0.926  0.372  0.372  1.0
  Al  Al7  1  0.427  0.871  0.871  1.0
  Al  Al8  1  0.372  0.372  0.926  1.0
  Al  Al9  1  0.871  0.871  0.427  1.0
  Al  Al10  1  0.372  0.926  0.372  1.0
  Al  Al11  1  0.871  0.427  0.871  1.0
  Al  Al12  1  0.577  0.131  0.131  1.0
  Al  Al13  1  0.077  0.631  0.631  1.0
  Al  Al14  1  0.131  0.131  0.577  1.0
  Al  Al15  1  0.631  0.631  0.077  1.0
  Al  Al16  1  0.131  0.577  0.131  1.0
  Al  Al17  1  0.631  0.077  0.631  1.0
  Al  Al18  1  0.503  0.503  0.999  1.0
  Al  Al19  1  0.002  0.002  0.500  1.0
  Al  Al20  1  0.503  0.999  0.503  1.0
  Al  Al21  1  0.002  0.500  0.002  1.0
  Al  Al22  1  0.999  0.503  0.503  1.0
  Al  Al23  1  0.500  0.002  0.002  1.0
[/CIF]
.
The compound described by ErGdAl6 crystallizes in the trigonal R3m space group. There are three inequivalent Er sites. In the first Er site, Er(1) is bonded to three equivalent Al(2), three equivalent Al(3), and six equivalent Al(5) atoms to form ErAl12 cuboctahedra that share corners with six equivalent Er(1)Al12 cuboctahedra,  a faceface with one Gd(1)Al12 cuboctahedra,  a faceface with one Gd(2)Al12 cuboctahedra, faces with three equivalent Er(3)Al12 cuboctahedra, and faces with three equivalent Gd(3)Al12 cuboctahedra. In the second Er site, Er(2) is bonded to three equivalent Al(1), three equivalent Al(4), and six equivalent Al(6) atoms to form ErAl12 cuboctahedra that share corners with six equivalent Er(2)Al12 cuboctahedra,  a faceface with one Er(3)Al12 cuboctahedra,  a faceface with one Gd(3)Al12 cuboctahedra, faces with three equivalent Gd(1)Al12 cuboctahedra, and faces with three equivalent Gd(2)Al12 cuboctahedra. In the third Er site, Er(3) is bonded to three equivalent Al(1), three equivalent Al(5), and six equivalent Al(3) atoms to form ErAl12 cuboctahedra that share corners with three equivalent Gd(3)Al12 cuboctahedra, corners with six equivalent Er(3)Al12 cuboctahedra,  a faceface with one Er(2)Al12 cuboctahedra, faces with three equivalent Er(1)Al12 cuboctahedra, and faces with three equivalent Gd(2)Al12 cuboctahedra. There are three inequivalent Gd sites. In the first Gd site, Gd(1) is bonded to three equivalent Al(2), three equivalent Al(6), and six equivalent Al(4) atoms to form GdAl12 cuboctahedra that share corners with three equivalent Gd(2)Al12 cuboctahedra, corners with six equivalent Gd(1)Al12 cuboctahedra,  a faceface with one Er(1)Al12 cuboctahedra, faces with three equivalent Er(2)Al12 cuboctahedra, and faces with three equivalent Gd(3)Al12 cuboctahedra. In the second Gd site, Gd(2) is bonded to three equivalent Al(3), three equivalent Al(6), and six equivalent Al(1) atoms to form GdAl12 cuboctahedra that share corners with three equivalent Gd(1)Al12 cuboctahedra, corners with six equivalent Gd(2)Al12 cuboctahedra,  a faceface with one Er(1)Al12 cuboctahedra, faces with three equivalent Er(2)Al12 cuboctahedra, and faces with three equivalent Er(3)Al12 cuboctahedra. In the third Gd site, Gd(3) is bonded to three equivalent Al(4), three equivalent Al(5), and six equivalent Al(2) atoms to form GdAl12 cuboctahedra that share corners with three equivalent Er(3)Al12 cuboctahedra, corners with six equivalent Gd(3)Al12 cuboctahedra,  a faceface with one Er(2)Al12 cuboctahedra, faces with three equivalent Er(1)Al12 cuboctahedra, and faces with three equivalent Gd(1)Al12 cuboctahedra. There are six inequivalent Al sites. In the first Al site, Al(1) is bonded in a 10-coordinate geometry to one Er(2), one Er(3), two equivalent Gd(2), two equivalent Al(1), two equivalent Al(3), and two equivalent Al(6) atoms. In the second Al site, Al(2) is bonded in a 10-coordinate geometry to one Er(1), one Gd(1), two equivalent Gd(3), two equivalent Al(2), two equivalent Al(4), and two equivalent Al(5) atoms. In the third Al site, Al(3) is bonded in a 10-coordinate geometry to one Er(1), two equivalent Er(3), one Gd(2), two equivalent Al(1), two equivalent Al(3), and two equivalent Al(5) atoms. In the fourth Al site, Al(4) is bonded in a 10-coordinate geometry to one Er(2), one Gd(3), two equivalent Gd(1), two equivalent Al(2), two equivalent Al(4), and two equivalent Al(6) atoms. In the fifth Al site, Al(5) is bonded in a 12-coordinate geometry to one Er(3), two equivalent Er(1), one Gd(3), two equivalent Al(2), two equivalent Al(3), and four equivalent Al(5) atoms. In the sixth Al site, Al(6) is bonded in a 12-coordinate geometry to two equivalent Er(2), one Gd(1), one Gd(2), two equivalent Al(1), two equivalent Al(4), and four equivalent Al(6) atoms. is represented by the CIF file [CIF]
data_GdErAl6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.579
_cell_length_b   14.579
_cell_length_c   14.579
_cell_angle_alpha   24.544
_cell_angle_beta   24.544
_cell_angle_gamma   24.544
_symmetry_Int_Tables_number   1
_cell_volume   470.094
_cell_formula_units_Z   3
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
  Gd  Gd0  1  0.111  0.111  0.111  1.0
  Gd  Gd1  1  0.892  0.892  0.892  1.0
  Gd  Gd2  1  0.392  0.392  0.392  1.0
  Er  Er3  1  0.001  0.001  0.001  1.0
  Er  Er4  1  0.501  0.501  0.501  1.0
  Er  Er5  1  0.611  0.611  0.611  1.0
  Al  Al6  1  0.926  0.372  0.372  1.0
  Al  Al7  1  0.427  0.871  0.871  1.0
  Al  Al8  1  0.372  0.372  0.926  1.0
  Al  Al9  1  0.871  0.871  0.427  1.0
  Al  Al10  1  0.372  0.926  0.372  1.0
  Al  Al11  1  0.871  0.427  0.871  1.0
  Al  Al12  1  0.577  0.131  0.131  1.0
  Al  Al13  1  0.077  0.631  0.631  1.0
  Al  Al14  1  0.131  0.131  0.577  1.0
  Al  Al15  1  0.631  0.631  0.077  1.0
  Al  Al16  1  0.131  0.577  0.131  1.0
  Al  Al17  1  0.631  0.077  0.631  1.0
  Al  Al18  1  0.503  0.503  0.999  1.0
  Al  Al19  1  0.002  0.002  0.500  1.0
  Al  Al20  1  0.503  0.999  0.503  1.0
  Al  Al21  1  0.002  0.500  0.002  1.0
  Al  Al22  1  0.999  0.503  0.503  1.0
  Al  Al23  1  0.500  0.002  0.002  1.0
[/CIF]
.