The structure described by Cr(FeAs3)2 crystallizes in the monoclinic P2/m space group. Cr(1) is bonded to one As(1), one As(2), two equivalent As(4), and two equivalent As(5) atoms to form CrAs6 octahedra that share corners with four equivalent Fe(2)As6 octahedra, corners with four equivalent Fe(3)As6 octahedra, and edges with two equivalent Cr(1)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-54°. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent As(3) and four equivalent As(6) atoms to form a mixture of corner and edge-sharing FeAs6 octahedra. The corner-sharing octahedral tilt angles are 53°. In the second Fe site, Fe(2) is bonded to one As(4), one As(6), two equivalent As(1), and two equivalent As(3) atoms to form FeAs6 octahedra that share corners with four equivalent Cr(1)As6 octahedra, corners with four equivalent Fe(1)As6 octahedra, and edges with two equivalent Fe(2)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-53°. In the third Fe site, Fe(3) is bonded to two equivalent As(5) and four equivalent As(2) atoms to form FeAs6 octahedra that share corners with eight equivalent Cr(1)As6 octahedra and edges with two equivalent Fe(3)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-54°. There are six inequivalent As sites. In the first As site, As(1) is bonded in a 3-coordinate geometry to one Cr(1) and two equivalent Fe(2) atoms. In the second As site, As(2) is bonded in a 3-coordinate geometry to one Cr(1) and two equivalent Fe(3) atoms. In the third As site, As(3) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Fe(2) atoms. In the fourth As site, As(4) is bonded in a 3-coordinate geometry to two equivalent Cr(1) and one Fe(2) atom. In the fifth As site, As(5) is bonded in a 3-coordinate geometry to two equivalent Cr(1) and one Fe(3) atom. In the sixth As site, As(6) is bonded in a 3-coordinate geometry to one Fe(2) and two equivalent Fe(1) atoms. is represented by the CIF file [CIF]
data_Cr(FeAs3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.900
_cell_length_b   5.394
_cell_length_c   18.309
_cell_angle_alpha   89.953
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   286.395
_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
  Cr  Cr0  1  0.500  0.500  0.667  1.0
  Cr  Cr1  1  0.500  0.500  0.333  1.0
  Fe  Fe2  1  0.500  0.500  0.000  1.0
  Fe  Fe3  1  0.000  0.002  0.836  1.0
  Fe  Fe4  1  0.000  0.000  0.500  1.0
  Fe  Fe5  1  0.000  0.998  0.164  1.0
  As  As6  1  0.500  0.316  0.792  1.0
  As  As7  1  0.500  0.317  0.457  1.0
  As  As8  1  0.500  0.321  0.119  1.0
  As  As9  1  0.500  0.683  0.543  1.0
  As  As10  1  0.500  0.684  0.208  1.0
  As  As11  1  0.500  0.679  0.881  1.0
  As  As12  1  0.000  0.832  0.716  1.0
  As  As13  1  0.000  0.833  0.381  1.0
  As  As14  1  0.000  0.820  0.045  1.0
  As  As15  1  0.000  0.167  0.619  1.0
  As  As16  1  0.000  0.168  0.284  1.0
  As  As17  1  0.000  0.180  0.955  1.0
[/CIF]
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The structure described by Cr(FeAs3)2 crystallizes in the monoclinic P2/m space group. Cr(1) is bonded to one As(1), one As(2), two equivalent As(4), and two equivalent As(5) atoms to form CrAs6 octahedra that share corners with four equivalent Fe(2)As6 octahedra, corners with four equivalent Fe(3)As6 octahedra, and edges with two equivalent Cr(1)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-54°. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent As(3) and four equivalent As(6) atoms to form a mixture of corner and edge-sharing FeAs6 octahedra. The corner-sharing octahedral tilt angles are 53°. In the second Fe site, Fe(2) is bonded to one As(4), one As(6), two equivalent As(1), and two equivalent As(3) atoms to form FeAs6 octahedra that share corners with four equivalent Cr(1)As6 octahedra, corners with four equivalent Fe(1)As6 octahedra, and edges with two equivalent Fe(2)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-53°. In the third Fe site, Fe(3) is bonded to two equivalent As(5) and four equivalent As(2) atoms to form FeAs6 octahedra that share corners with eight equivalent Cr(1)As6 octahedra and edges with two equivalent Fe(3)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-54°. There are six inequivalent As sites. In the first As site, As(1) is bonded in a 3-coordinate geometry to one Cr(1) and two equivalent Fe(2) atoms. In the second As site, As(2) is bonded in a 3-coordinate geometry to one Cr(1) and two equivalent Fe(3) atoms. In the third As site, As(3) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Fe(2) atoms. In the fourth As site, As(4) is bonded in a 3-coordinate geometry to two equivalent Cr(1) and one Fe(2) atom. In the fifth As site, As(5) is bonded in a 3-coordinate geometry to two equivalent Cr(1) and one Fe(3) atom. In the sixth As site, As(6) is bonded in a 3-coordinate geometry to one Fe(2) and two equivalent Fe(1) atoms. is represented by the CIF file [CIF]
data_Cr(FeAs3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.900
_cell_length_b   5.394
_cell_length_c   18.309
_cell_angle_alpha   89.953
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   286.395
_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
  Cr  Cr0  1  0.500  0.500  0.667  1.0
  Cr  Cr1  1  0.500  0.500  0.333  1.0
  Fe  Fe2  1  0.500  0.500  0.000  1.0
  Fe  Fe3  1  0.000  0.002  0.836  1.0
  Fe  Fe4  1  0.000  0.000  0.500  1.0
  Fe  Fe5  1  0.000  0.998  0.164  1.0
  As  As6  1  0.500  0.316  0.792  1.0
  As  As7  1  0.500  0.317  0.457  1.0
  As  As8  1  0.500  0.321  0.119  1.0
  As  As9  1  0.500  0.683  0.543  1.0
  As  As10  1  0.500  0.684  0.208  1.0
  As  As11  1  0.500  0.679  0.881  1.0
  As  As12  1  0.000  0.832  0.716  1.0
  As  As13  1  0.000  0.833  0.381  1.0
  As  As14  1  0.000  0.820  0.045  1.0
  As  As15  1  0.000  0.167  0.619  1.0
  As  As16  1  0.000  0.168  0.284  1.0
  As  As17  1  0.000  0.180  0.955  1.0
[/CIF]
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