The material described by Sm2Fe2As2O crystallizes in the tetragonal P-4m2 space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a distorted bent 120 degrees geometry to four equivalent As(1) and two equivalent O(1) atoms. In the second Sm site, Sm(1) is bonded in a distorted bent 120 degrees geometry to four equivalent As(1) and two equivalent O(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to four equivalent As(1) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. In the second Fe site, Fe(2) is bonded to four equivalent As(1) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. As(1) is bonded in a 8-coordinate geometry to four equivalent Sm(1), two equivalent Fe(1), and two equivalent Fe(2) atoms. O(1) is bonded to four Sm(1,1) atoms to form corner-sharing OSm4 tetrahedra. is represented by the CIF card [CIF]
data_Sm2Fe2As2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.992
_cell_length_b   3.992
_cell_length_c   8.088
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   128.901
_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
  Sm  Sm0  1  0.750  0.750  0.839  1.0
  Sm  Sm1  1  0.250  0.250  0.161  1.0
  Fe  Fe2  1  0.750  0.250  0.500  1.0
  Fe  Fe3  1  0.250  0.750  0.500  1.0
  As  As4  1  0.750  0.750  0.318  1.0
  As  As5  1  0.250  0.250  0.682  1.0
  O  O6  1  0.750  0.250  0.000  1.0
[/CIF]
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The material described by Sm2Fe2As2O crystallizes in the tetragonal P-4m2 space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a distorted bent 120 degrees geometry to four equivalent As(1) and two equivalent O(1) atoms. In the second Sm site, Sm(1) is bonded in a distorted bent 120 degrees geometry to four equivalent As(1) and two equivalent O(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to four equivalent As(1) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. In the second Fe site, Fe(2) is bonded to four equivalent As(1) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. As(1) is bonded in a 8-coordinate geometry to four equivalent Sm(1), two equivalent Fe(1), and two equivalent Fe(2) atoms. O(1) is bonded to four Sm(1,1) atoms to form corner-sharing OSm4 tetrahedra. is represented by the CIF card [CIF]
data_Sm2Fe2As2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.992
_cell_length_b   3.992
_cell_length_c   8.088
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   128.901
_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
  Sm  Sm0  1  0.750  0.750  0.839  1.0
  Sm  Sm1  1  0.250  0.250  0.161  1.0
  Fe  Fe2  1  0.750  0.250  0.500  1.0
  Fe  Fe3  1  0.250  0.750  0.500  1.0
  As  As4  1  0.750  0.750  0.318  1.0
  As  As5  1  0.250  0.250  0.682  1.0
  O  O6  1  0.750  0.250  0.000  1.0
[/CIF]
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