The material described by LaYFe2(AsO)2 crystallizes in the tetragonal P4mm space group. La(1) is bonded in a 4-coordinate geometry to four equivalent As(1) and four equivalent O(1) atoms. Y(1) is bonded in a 4-coordinate geometry to four equivalent As(2) and four equivalent O(1) atoms. Fe(1) is bonded to two equivalent As(1) and two equivalent As(2) atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Fe(1) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to four equivalent Y(1) and four equivalent Fe(1) atoms. O(1) is bonded to two equivalent La(1) and two equivalent Y(1) atoms to form a mixture of edge and corner-sharing OLa2Y2 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_LaYFe2(AsO)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.114
_cell_length_b   4.114
_cell_length_c   8.981
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   151.992
_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
  La  La0  1  0.000  0.000  0.129  1.0
  Y  Y1  1  0.500  0.500  0.880  1.0
  Fe  Fe2  1  0.500  0.000  0.502  1.0
  Fe  Fe3  1  0.000  0.500  0.502  1.0
  As  As4  1  0.500  0.500  0.325  1.0
  As  As5  1  0.000  0.000  0.678  1.0
  O  O6  1  0.500  0.000  0.992  1.0
  O  O7  1  0.000  0.500  0.992  1.0
[/CIF]
.
The material described by LaYFe2(AsO)2 crystallizes in the tetragonal P4mm space group. La(1) is bonded in a 4-coordinate geometry to four equivalent As(1) and four equivalent O(1) atoms. Y(1) is bonded in a 4-coordinate geometry to four equivalent As(2) and four equivalent O(1) atoms. Fe(1) is bonded to two equivalent As(1) and two equivalent As(2) atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Fe(1) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to four equivalent Y(1) and four equivalent Fe(1) atoms. O(1) is bonded to two equivalent La(1) and two equivalent Y(1) atoms to form a mixture of edge and corner-sharing OLa2Y2 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_LaYFe2(AsO)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.114
_cell_length_b   4.114
_cell_length_c   8.981
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   151.992
_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
  La  La0  1  0.000  0.000  0.129  1.0
  Y  Y1  1  0.500  0.500  0.880  1.0
  Fe  Fe2  1  0.500  0.000  0.502  1.0
  Fe  Fe3  1  0.000  0.500  0.502  1.0
  As  As4  1  0.500  0.500  0.325  1.0
  As  As5  1  0.000  0.000  0.678  1.0
  O  O6  1  0.500  0.000  0.992  1.0
  O  O7  1  0.000  0.500  0.992  1.0
[/CIF]
.