The crystal structure described by RbCr2FeO8 crystallizes in the orthorhombic Pnma space group. Rb(1) is bonded in a 10-coordinate geometry to one O(2), two equivalent O(4), two equivalent O(5), two equivalent O(6), and three equivalent O(1) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), one O(4), and two equivalent O(5) atoms to form CrO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-40°. In the second Cr site, Cr(2) is bonded to one O(1), one O(3), 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 14-34°. Fe(1) is bonded to one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with three equivalent Cr(1)O4 tetrahedra and corners with three equivalent Cr(2)O4 tetrahedra. There are six inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Cr(1), and one Fe(1) atom. In the second O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Cr(2), and one Fe(1) atom. In the third O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Cr(2) atom. In the fourth O site, O(2) is bonded in a single-bond geometry to one Rb(1) and one Cr(1) atom. In the fifth O site, O(3) is bonded in a linear geometry to one Cr(2) and one Fe(1) atom. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(1), one Cr(1), and one Fe(1) atom. is represented by the CIF card [CIF]
data_RbCr2FeO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.544
_cell_length_b   8.978
_cell_length_c   14.971
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   745.214
_cell_formula_units_Z   4
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
  Rb  Rb0  1  0.250  0.949  0.380  1.0
  Rb  Rb1  1  0.750  0.051  0.620  1.0
  Rb  Rb2  1  0.750  0.449  0.120  1.0
  Rb  Rb3  1  0.250  0.551  0.880  1.0
  Cr  Cr4  1  0.750  0.244  0.336  1.0
  Cr  Cr5  1  0.250  0.756  0.664  1.0
  Cr  Cr6  1  0.250  0.744  0.164  1.0
  Cr  Cr7  1  0.750  0.256  0.836  1.0
  Cr  Cr8  1  0.750  0.682  0.437  1.0
  Cr  Cr9  1  0.250  0.318  0.563  1.0
  Cr  Cr10  1  0.250  0.182  0.063  1.0
  Cr  Cr11  1  0.750  0.818  0.937  1.0
  Fe  Fe12  1  0.250  0.493  0.344  1.0
  Fe  Fe13  1  0.750  0.507  0.656  1.0
  Fe  Fe14  1  0.750  0.993  0.156  1.0
  Fe  Fe15  1  0.250  0.007  0.844  1.0
  O  O16  1  0.750  0.859  0.460  1.0
  O  O17  1  0.250  0.141  0.540  1.0
  O  O18  1  0.250  0.359  0.040  1.0
  O  O19  1  0.750  0.641  0.960  1.0
  O  O20  1  0.250  0.712  0.058  1.0
  O  O21  1  0.750  0.288  0.942  1.0
  O  O22  1  0.750  0.212  0.442  1.0
  O  O23  1  0.250  0.788  0.558  1.0
  O  O24  1  0.250  0.419  0.470  1.0
  O  O25  1  0.750  0.581  0.530  1.0
  O  O26  1  0.750  0.919  0.030  1.0
  O  O27  1  0.250  0.081  0.970  1.0
  O  O28  1  0.250  0.578  0.218  1.0
  O  O29  1  0.750  0.422  0.782  1.0
  O  O30  1  0.750  0.078  0.282  1.0
  O  O31  1  0.250  0.922  0.718  1.0
  O  O32  1  0.996  0.343  0.308  1.0
  O  O33  1  0.496  0.657  0.692  1.0
  O  O34  1  0.004  0.843  0.192  1.0
  O  O35  1  0.504  0.157  0.808  1.0
  O  O36  1  0.004  0.657  0.692  1.0
  O  O37  1  0.504  0.343  0.308  1.0
  O  O38  1  0.996  0.157  0.808  1.0
  O  O39  1  0.496  0.843  0.192  1.0
  O  O40  1  0.002  0.144  0.125  1.0
  O  O41  1  0.502  0.856  0.875  1.0
  O  O42  1  0.998  0.644  0.375  1.0
  O  O43  1  0.498  0.356  0.625  1.0
  O  O44  1  0.998  0.856  0.875  1.0
  O  O45  1  0.498  0.144  0.125  1.0
  O  O46  1  0.002  0.356  0.625  1.0
  O  O47  1  0.502  0.644  0.375  1.0
[/CIF]
.
The crystal structure described by RbCr2FeO8 crystallizes in the orthorhombic Pnma space group. Rb(1) is bonded in a 10-coordinate geometry to one O(2), two equivalent O(4), two equivalent O(5), two equivalent O(6), and three equivalent O(1) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), one O(4), and two equivalent O(5) atoms to form CrO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-40°. In the second Cr site, Cr(2) is bonded to one O(1), one O(3), 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 14-34°. Fe(1) is bonded to one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with three equivalent Cr(1)O4 tetrahedra and corners with three equivalent Cr(2)O4 tetrahedra. There are six inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Cr(1), and one Fe(1) atom. In the second O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Cr(2), and one Fe(1) atom. In the third O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Cr(2) atom. In the fourth O site, O(2) is bonded in a single-bond geometry to one Rb(1) and one Cr(1) atom. In the fifth O site, O(3) is bonded in a linear geometry to one Cr(2) and one Fe(1) atom. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(1), one Cr(1), and one Fe(1) atom. is represented by the CIF card [CIF]
data_RbCr2FeO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.544
_cell_length_b   8.978
_cell_length_c   14.971
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   745.214
_cell_formula_units_Z   4
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
  Rb  Rb0  1  0.250  0.949  0.380  1.0
  Rb  Rb1  1  0.750  0.051  0.620  1.0
  Rb  Rb2  1  0.750  0.449  0.120  1.0
  Rb  Rb3  1  0.250  0.551  0.880  1.0
  Cr  Cr4  1  0.750  0.244  0.336  1.0
  Cr  Cr5  1  0.250  0.756  0.664  1.0
  Cr  Cr6  1  0.250  0.744  0.164  1.0
  Cr  Cr7  1  0.750  0.256  0.836  1.0
  Cr  Cr8  1  0.750  0.682  0.437  1.0
  Cr  Cr9  1  0.250  0.318  0.563  1.0
  Cr  Cr10  1  0.250  0.182  0.063  1.0
  Cr  Cr11  1  0.750  0.818  0.937  1.0
  Fe  Fe12  1  0.250  0.493  0.344  1.0
  Fe  Fe13  1  0.750  0.507  0.656  1.0
  Fe  Fe14  1  0.750  0.993  0.156  1.0
  Fe  Fe15  1  0.250  0.007  0.844  1.0
  O  O16  1  0.750  0.859  0.460  1.0
  O  O17  1  0.250  0.141  0.540  1.0
  O  O18  1  0.250  0.359  0.040  1.0
  O  O19  1  0.750  0.641  0.960  1.0
  O  O20  1  0.250  0.712  0.058  1.0
  O  O21  1  0.750  0.288  0.942  1.0
  O  O22  1  0.750  0.212  0.442  1.0
  O  O23  1  0.250  0.788  0.558  1.0
  O  O24  1  0.250  0.419  0.470  1.0
  O  O25  1  0.750  0.581  0.530  1.0
  O  O26  1  0.750  0.919  0.030  1.0
  O  O27  1  0.250  0.081  0.970  1.0
  O  O28  1  0.250  0.578  0.218  1.0
  O  O29  1  0.750  0.422  0.782  1.0
  O  O30  1  0.750  0.078  0.282  1.0
  O  O31  1  0.250  0.922  0.718  1.0
  O  O32  1  0.996  0.343  0.308  1.0
  O  O33  1  0.496  0.657  0.692  1.0
  O  O34  1  0.004  0.843  0.192  1.0
  O  O35  1  0.504  0.157  0.808  1.0
  O  O36  1  0.004  0.657  0.692  1.0
  O  O37  1  0.504  0.343  0.308  1.0
  O  O38  1  0.996  0.157  0.808  1.0
  O  O39  1  0.496  0.843  0.192  1.0
  O  O40  1  0.002  0.144  0.125  1.0
  O  O41  1  0.502  0.856  0.875  1.0
  O  O42  1  0.998  0.644  0.375  1.0
  O  O43  1  0.498  0.356  0.625  1.0
  O  O44  1  0.998  0.856  0.875  1.0
  O  O45  1  0.498  0.144  0.125  1.0
  O  O46  1  0.002  0.356  0.625  1.0
  O  O47  1  0.502  0.644  0.375  1.0
[/CIF]
.