The compound described by Rb4FeO4 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. In the second Rb site, Rb(2) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted RbO5 trigonal bipyramids that share corners with three equivalent Fe(1)O4 tetrahedra, corners with two equivalent Rb(2)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O4 tetrahedra, and  an edgeedge with one Rb(2)O5 trigonal bipyramid. In the third Rb site, Rb(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. In the fourth Rb site, Rb(4) is bonded in a 4-coordinate geometry to one O(3) and three equivalent O(4) atoms. Fe(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted FeO4 tetrahedra that share corners with three equivalent Rb(2)O5 trigonal bipyramids and  an edgeedge with one Rb(2)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Rb(3), two equivalent Rb(1), two equivalent Rb(2), and one Fe(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Rb(3), two equivalent Rb(1), two equivalent Rb(2), and one Fe(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one Rb(1), one Rb(2), one Rb(4), two equivalent Rb(3), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Rb(3), three equivalent Rb(4), and one Fe(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Rb4FeO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.602
_cell_length_b   10.618
_cell_length_c   11.165
_cell_angle_alpha   69.222
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   731.773
_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  0.690  0.274  0.100  1.0
  Rb  Rb1  1  0.200  0.402  0.108  1.0
  Rb  Rb2  1  0.372  0.059  0.344  1.0
  Rb  Rb3  1  0.810  0.774  0.100  1.0
  Rb  Rb4  1  0.300  0.902  0.108  1.0
  Rb  Rb5  1  0.929  0.215  0.428  1.0
  Rb  Rb6  1  0.128  0.559  0.344  1.0
  Rb  Rb7  1  0.429  0.285  0.572  1.0
  Rb  Rb8  1  0.571  0.715  0.428  1.0
  Rb  Rb9  1  0.872  0.441  0.656  1.0
  Rb  Rb10  1  0.071  0.785  0.572  1.0
  Rb  Rb11  1  0.700  0.098  0.892  1.0
  Rb  Rb12  1  0.190  0.226  0.900  1.0
  Rb  Rb13  1  0.628  0.941  0.656  1.0
  Rb  Rb14  1  0.800  0.598  0.892  1.0
  Rb  Rb15  1  0.310  0.726  0.900  1.0
  Fe  Fe16  1  0.619  0.479  0.263  1.0
  Fe  Fe17  1  0.881  0.979  0.263  1.0
  Fe  Fe18  1  0.119  0.021  0.737  1.0
  Fe  Fe19  1  0.381  0.521  0.737  1.0
  O  O20  1  0.041  0.111  0.156  1.0
  O  O21  1  0.847  0.493  0.169  1.0
  O  O22  1  0.460  0.332  0.309  1.0
  O  O23  1  0.459  0.611  0.156  1.0
  O  O24  1  0.653  0.993  0.169  1.0
  O  O25  1  0.723  0.470  0.412  1.0
  O  O26  1  0.223  0.030  0.588  1.0
  O  O27  1  0.040  0.832  0.309  1.0
  O  O28  1  0.960  0.168  0.691  1.0
  O  O29  1  0.777  0.970  0.412  1.0
  O  O30  1  0.277  0.530  0.588  1.0
  O  O31  1  0.347  0.007  0.831  1.0
  O  O32  1  0.541  0.389  0.844  1.0
  O  O33  1  0.540  0.668  0.691  1.0
  O  O34  1  0.153  0.507  0.831  1.0
  O  O35  1  0.959  0.889  0.844  1.0
[/CIF]
.
The compound described by Rb4FeO4 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. In the second Rb site, Rb(2) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted RbO5 trigonal bipyramids that share corners with three equivalent Fe(1)O4 tetrahedra, corners with two equivalent Rb(2)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O4 tetrahedra, and  an edgeedge with one Rb(2)O5 trigonal bipyramid. In the third Rb site, Rb(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. In the fourth Rb site, Rb(4) is bonded in a 4-coordinate geometry to one O(3) and three equivalent O(4) atoms. Fe(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted FeO4 tetrahedra that share corners with three equivalent Rb(2)O5 trigonal bipyramids and  an edgeedge with one Rb(2)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Rb(3), two equivalent Rb(1), two equivalent Rb(2), and one Fe(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Rb(3), two equivalent Rb(1), two equivalent Rb(2), and one Fe(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one Rb(1), one Rb(2), one Rb(4), two equivalent Rb(3), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Rb(3), three equivalent Rb(4), and one Fe(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Rb4FeO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.602
_cell_length_b   10.618
_cell_length_c   11.165
_cell_angle_alpha   69.222
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   731.773
_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  0.690  0.274  0.100  1.0
  Rb  Rb1  1  0.200  0.402  0.108  1.0
  Rb  Rb2  1  0.372  0.059  0.344  1.0
  Rb  Rb3  1  0.810  0.774  0.100  1.0
  Rb  Rb4  1  0.300  0.902  0.108  1.0
  Rb  Rb5  1  0.929  0.215  0.428  1.0
  Rb  Rb6  1  0.128  0.559  0.344  1.0
  Rb  Rb7  1  0.429  0.285  0.572  1.0
  Rb  Rb8  1  0.571  0.715  0.428  1.0
  Rb  Rb9  1  0.872  0.441  0.656  1.0
  Rb  Rb10  1  0.071  0.785  0.572  1.0
  Rb  Rb11  1  0.700  0.098  0.892  1.0
  Rb  Rb12  1  0.190  0.226  0.900  1.0
  Rb  Rb13  1  0.628  0.941  0.656  1.0
  Rb  Rb14  1  0.800  0.598  0.892  1.0
  Rb  Rb15  1  0.310  0.726  0.900  1.0
  Fe  Fe16  1  0.619  0.479  0.263  1.0
  Fe  Fe17  1  0.881  0.979  0.263  1.0
  Fe  Fe18  1  0.119  0.021  0.737  1.0
  Fe  Fe19  1  0.381  0.521  0.737  1.0
  O  O20  1  0.041  0.111  0.156  1.0
  O  O21  1  0.847  0.493  0.169  1.0
  O  O22  1  0.460  0.332  0.309  1.0
  O  O23  1  0.459  0.611  0.156  1.0
  O  O24  1  0.653  0.993  0.169  1.0
  O  O25  1  0.723  0.470  0.412  1.0
  O  O26  1  0.223  0.030  0.588  1.0
  O  O27  1  0.040  0.832  0.309  1.0
  O  O28  1  0.960  0.168  0.691  1.0
  O  O29  1  0.777  0.970  0.412  1.0
  O  O30  1  0.277  0.530  0.588  1.0
  O  O31  1  0.347  0.007  0.831  1.0
  O  O32  1  0.541  0.389  0.844  1.0
  O  O33  1  0.540  0.668  0.691  1.0
  O  O34  1  0.153  0.507  0.831  1.0
  O  O35  1  0.959  0.889  0.844  1.0
[/CIF]
.