The structure described by NaSr2(FeAs)6 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a distorted body-centered cubic geometry to two equivalent As(1), two equivalent As(2), and four equivalent As(3) atoms. Sr(1) is bonded in a distorted body-centered cubic geometry to two equivalent As(3), three equivalent As(1), and three equivalent As(2) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one As(1), one As(3), and two equivalent As(2) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. In the second Fe site, Fe(2) is bonded to two equivalent As(1) and two equivalent As(3) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to one Na(1), three equivalent Sr(1), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to one Na(1), three equivalent Sr(1), and four equivalent Fe(1) atoms. In the third As site, As(3) is bonded in a 8-coordinate geometry to two equivalent Na(1), two equivalent Sr(1), two equivalent Fe(1), and two equivalent Fe(2) atoms. is represented by the CIF card [CIF]
data_NaSr2(FeAs)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.516
_cell_length_b   6.517
_cell_length_c   8.855
_cell_angle_alpha   114.122
_cell_angle_beta   71.853
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   273.094
_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
  Na  Na0  1  0.000  0.000  0.000  1.0
  Sr  Sr1  1  0.337  0.001  0.326  1.0
  Sr  Sr2  1  0.663  0.999  0.674  1.0
  Fe  Fe3  1  0.417  0.498  0.667  1.0
  Fe  Fe4  1  0.083  0.502  0.333  1.0
  Fe  Fe5  1  0.750  0.500  0.000  1.0
  Fe  Fe6  1  0.250  0.500  0.000  1.0
  Fe  Fe7  1  0.917  0.498  0.667  1.0
  Fe  Fe8  1  0.583  0.502  0.333  1.0
  As  As9  1  0.120  0.286  0.760  1.0
  As  As10  1  0.785  0.291  0.430  1.0
  As  As11  1  0.451  0.288  0.098  1.0
  As  As12  1  0.549  0.712  0.902  1.0
  As  As13  1  0.215  0.709  0.570  1.0
  As  As14  1  0.880  0.714  0.240  1.0
[/CIF]
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The structure described by NaSr2(FeAs)6 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a distorted body-centered cubic geometry to two equivalent As(1), two equivalent As(2), and four equivalent As(3) atoms. Sr(1) is bonded in a distorted body-centered cubic geometry to two equivalent As(3), three equivalent As(1), and three equivalent As(2) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one As(1), one As(3), and two equivalent As(2) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. In the second Fe site, Fe(2) is bonded to two equivalent As(1) and two equivalent As(3) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to one Na(1), three equivalent Sr(1), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to one Na(1), three equivalent Sr(1), and four equivalent Fe(1) atoms. In the third As site, As(3) is bonded in a 8-coordinate geometry to two equivalent Na(1), two equivalent Sr(1), two equivalent Fe(1), and two equivalent Fe(2) atoms. is represented by the CIF card [CIF]
data_NaSr2(FeAs)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.516
_cell_length_b   6.517
_cell_length_c   8.855
_cell_angle_alpha   114.122
_cell_angle_beta   71.853
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   273.094
_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
  Na  Na0  1  0.000  0.000  0.000  1.0
  Sr  Sr1  1  0.337  0.001  0.326  1.0
  Sr  Sr2  1  0.663  0.999  0.674  1.0
  Fe  Fe3  1  0.417  0.498  0.667  1.0
  Fe  Fe4  1  0.083  0.502  0.333  1.0
  Fe  Fe5  1  0.750  0.500  0.000  1.0
  Fe  Fe6  1  0.250  0.500  0.000  1.0
  Fe  Fe7  1  0.917  0.498  0.667  1.0
  Fe  Fe8  1  0.583  0.502  0.333  1.0
  As  As9  1  0.120  0.286  0.760  1.0
  As  As10  1  0.785  0.291  0.430  1.0
  As  As11  1  0.451  0.288  0.098  1.0
  As  As12  1  0.549  0.712  0.902  1.0
  As  As13  1  0.215  0.709  0.570  1.0
  As  As14  1  0.880  0.714  0.240  1.0
[/CIF]
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