The crystal structure described by SmFeAsO is Parent of FeAs superconductors structured and crystallizes in the tetragonal P4/nmm space group. Sm(1) is bonded in a 4-coordinate geometry to four equivalent As(1) and four equivalent O(1) atoms. Fe(1) is bonded to four equivalent As(1) atoms to form a mixture of distorted edge and corner-sharing FeAs4 tetrahedra. As(1) is bonded in a 8-coordinate geometry to four equivalent Sm(1) and four equivalent Fe(1) atoms. O(1) is bonded to four equivalent Sm(1) atoms to form a mixture of edge and corner-sharing OSm4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_SmFeAsO
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.026
_cell_length_b   4.026
_cell_length_c   9.047
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   146.672
_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
  Sm  Sm0  1  0.500  0.000  0.874  1.0
  Sm  Sm1  1  0.000  0.500  0.126  1.0
  Fe  Fe2  1  0.000  0.000  0.500  1.0
  Fe  Fe3  1  0.500  0.500  0.500  1.0
  As  As4  1  0.500  0.000  0.321  1.0
  As  As5  1  0.000  0.500  0.679  1.0
  O  O6  1  0.000  0.000  0.000  1.0
  O  O7  1  0.500  0.500  0.000  1.0
[/CIF]
.
The crystal structure described by SmFeAsO is Parent of FeAs superconductors structured and crystallizes in the tetragonal P4/nmm space group. Sm(1) is bonded in a 4-coordinate geometry to four equivalent As(1) and four equivalent O(1) atoms. Fe(1) is bonded to four equivalent As(1) atoms to form a mixture of distorted edge and corner-sharing FeAs4 tetrahedra. As(1) is bonded in a 8-coordinate geometry to four equivalent Sm(1) and four equivalent Fe(1) atoms. O(1) is bonded to four equivalent Sm(1) atoms to form a mixture of edge and corner-sharing OSm4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_SmFeAsO
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.026
_cell_length_b   4.026
_cell_length_c   9.047
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   146.672
_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
  Sm  Sm0  1  0.500  0.000  0.874  1.0
  Sm  Sm1  1  0.000  0.500  0.126  1.0
  Fe  Fe2  1  0.000  0.000  0.500  1.0
  Fe  Fe3  1  0.500  0.500  0.500  1.0
  As  As4  1  0.500  0.000  0.321  1.0
  As  As5  1  0.000  0.500  0.679  1.0
  O  O6  1  0.000  0.000  0.000  1.0
  O  O7  1  0.500  0.500  0.000  1.0
[/CIF]
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