The compound described by KCr2FeO9 crystallizes in the monoclinic P2_1/m space group. K(1) is bonded in a 10-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(6), and three equivalent O(5) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form CrO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 36°. In the second Cr site, Cr(2) is bonded to one O(4), one O(5), and two equivalent O(6) atoms to form CrO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-44°. Fe(1) is bonded to one O(4), one O(7), two equivalent O(3), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with two equivalent Cr(1)O4 tetrahedra and corners with three equivalent Cr(2)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1) and one Cr(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to two equivalent K(1) and one Cr(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one K(1), one Cr(1), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Cr(2) and one Fe(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to three equivalent K(1) and one Cr(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one K(1), one Cr(2), and one Fe(1) atom. In the seventh O site, O(7) is bonded in a single-bond geometry to one Fe(1) atom. is represented by the CIF file [CIF]
data_KCr2FeO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.577
_cell_length_b   7.892
_cell_length_c   9.623
_cell_angle_alpha   101.604
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   414.891
_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
  K  K0  1  0.250  0.577  0.213  1.0
  K  K1  1  0.750  0.423  0.787  1.0
  Cr  Cr2  1  0.250  0.657  0.649  1.0
  Cr  Cr3  1  0.750  0.343  0.351  1.0
  Cr  Cr4  1  0.250  0.158  0.879  1.0
  Cr  Cr5  1  0.750  0.842  0.121  1.0
  Fe  Fe6  1  0.250  0.087  0.230  1.0
  Fe  Fe7  1  0.750  0.913  0.770  1.0
  O  O8  1  0.250  0.719  0.498  1.0
  O  O9  1  0.750  0.281  0.502  1.0
  O  O10  1  0.250  0.447  0.624  1.0
  O  O11  1  0.750  0.553  0.376  1.0
  O  O12  1  0.502  0.731  0.743  1.0
  O  O13  1  0.002  0.269  0.257  1.0
  O  O14  1  0.498  0.269  0.257  1.0
  O  O15  1  0.998  0.731  0.743  1.0
  O  O16  1  0.250  0.062  0.018  1.0
  O  O17  1  0.750  0.938  0.982  1.0
  O  O18  1  0.250  0.366  0.933  1.0
  O  O19  1  0.750  0.634  0.067  1.0
  O  O20  1  0.500  0.100  0.782  1.0
  O  O21  1  0.000  0.900  0.218  1.0
  O  O22  1  0.500  0.900  0.218  1.0
  O  O23  1  1.000  0.100  0.782  1.0
  O  O24  1  0.250  0.100  0.450  1.0
  O  O25  1  0.750  0.900  0.550  1.0
[/CIF]
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The compound described by KCr2FeO9 crystallizes in the monoclinic P2_1/m space group. K(1) is bonded in a 10-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(6), and three equivalent O(5) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form CrO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 36°. In the second Cr site, Cr(2) is bonded to one O(4), one O(5), and two equivalent O(6) atoms to form CrO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-44°. Fe(1) is bonded to one O(4), one O(7), two equivalent O(3), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with two equivalent Cr(1)O4 tetrahedra and corners with three equivalent Cr(2)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1) and one Cr(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to two equivalent K(1) and one Cr(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one K(1), one Cr(1), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Cr(2) and one Fe(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to three equivalent K(1) and one Cr(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one K(1), one Cr(2), and one Fe(1) atom. In the seventh O site, O(7) is bonded in a single-bond geometry to one Fe(1) atom. is represented by the CIF file [CIF]
data_KCr2FeO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.577
_cell_length_b   7.892
_cell_length_c   9.623
_cell_angle_alpha   101.604
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   414.891
_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
  K  K0  1  0.250  0.577  0.213  1.0
  K  K1  1  0.750  0.423  0.787  1.0
  Cr  Cr2  1  0.250  0.657  0.649  1.0
  Cr  Cr3  1  0.750  0.343  0.351  1.0
  Cr  Cr4  1  0.250  0.158  0.879  1.0
  Cr  Cr5  1  0.750  0.842  0.121  1.0
  Fe  Fe6  1  0.250  0.087  0.230  1.0
  Fe  Fe7  1  0.750  0.913  0.770  1.0
  O  O8  1  0.250  0.719  0.498  1.0
  O  O9  1  0.750  0.281  0.502  1.0
  O  O10  1  0.250  0.447  0.624  1.0
  O  O11  1  0.750  0.553  0.376  1.0
  O  O12  1  0.502  0.731  0.743  1.0
  O  O13  1  0.002  0.269  0.257  1.0
  O  O14  1  0.498  0.269  0.257  1.0
  O  O15  1  0.998  0.731  0.743  1.0
  O  O16  1  0.250  0.062  0.018  1.0
  O  O17  1  0.750  0.938  0.982  1.0
  O  O18  1  0.250  0.366  0.933  1.0
  O  O19  1  0.750  0.634  0.067  1.0
  O  O20  1  0.500  0.100  0.782  1.0
  O  O21  1  0.000  0.900  0.218  1.0
  O  O22  1  0.500  0.900  0.218  1.0
  O  O23  1  1.000  0.100  0.782  1.0
  O  O24  1  0.250  0.100  0.450  1.0
  O  O25  1  0.750  0.900  0.550  1.0
[/CIF]
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