The structure described by Fe21HO32 crystallizes in the trigonal R3m space group. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(4), two equivalent O(5), and two equivalent O(8) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(5)O4 tetrahedra,  a cornercorner with one Fe(7)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, corners with two equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with four equivalent Fe(3)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(3), two equivalent O(5), and two equivalent O(7) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(7)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, corners with three equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form FeO6 octahedra that share  a cornercorner with one Fe(5)O4 tetrahedra,  a cornercorner with one Fe(7)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, corners with two equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(6), one O(7), and two equivalent O(8) atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-59°. In the fifth Fe site, Fe(5) is bonded to one O(9) and three equivalent O(4) atoms to form FeO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with six equivalent Fe(3)O6 octahedra, and  a cornercorner with one Fe(8)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-64°. In the sixth Fe site, Fe(6) is bonded to one O(10), one O(3), and two equivalent O(5) atoms to form FeO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, corners with four equivalent Fe(3)O6 octahedra, and  a cornercorner with one Fe(8)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-62°. In the seventh Fe site, Fe(7) is bonded to one O(1) and three equivalent O(2) atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-56°. In the eighth Fe site, Fe(8) is bonded to one O(9) and three equivalent O(10) atoms to form corner-sharing FeO4 tetrahedra. H(1) is bonded in a trigonal non-coplanar geometry to three equivalent O(7) atoms. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Fe(7) and three equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(7), and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Fe(2), one Fe(6), and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded to one Fe(1), one Fe(5), and two equivalent Fe(3) atoms to form distorted corner-sharing OFe4 trigonal pyramids. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(2), one Fe(3), and one Fe(6) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(3) atoms. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Fe(4), two equivalent Fe(2), and one H(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(4) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Fe(5) and one Fe(8) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Fe(6) and one Fe(8) atom. is represented by the CIF card [CIF]
data_Fe21HO32
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.531
_cell_length_b   8.531
_cell_length_c   8.531
_cell_angle_alpha   89.297
_cell_angle_beta   89.297
_cell_angle_gamma   89.297
_symmetry_Int_Tables_number   1
_cell_volume   620.774
_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
  Fe  Fe0  1  0.616  0.133  0.133  1.0
  Fe  Fe1  1  0.133  0.616  0.133  1.0
  Fe  Fe2  1  0.133  0.133  0.616  1.0
  Fe  Fe3  1  0.624  0.877  0.877  1.0
  Fe  Fe4  1  0.131  0.380  0.865  1.0
  Fe  Fe5  1  0.131  0.865  0.380  1.0
  Fe  Fe6  1  0.380  0.865  0.131  1.0
  Fe  Fe7  1  0.865  0.380  0.131  1.0
  Fe  Fe8  1  0.877  0.877  0.624  1.0
  Fe  Fe9  1  0.380  0.131  0.865  1.0
  Fe  Fe10  1  0.877  0.624  0.877  1.0
  Fe  Fe11  1  0.865  0.131  0.380  1.0
  Fe  Fe12  1  0.501  0.981  0.501  1.0
  Fe  Fe13  1  0.501  0.501  0.981  1.0
  Fe  Fe14  1  0.981  0.501  0.501  1.0
  Fe  Fe15  1  0.249  0.249  0.249  1.0
  Fe  Fe16  1  0.258  0.750  0.750  1.0
  Fe  Fe17  1  0.750  0.750  0.258  1.0
  Fe  Fe18  1  0.750  0.258  0.750  1.0
  Fe  Fe19  1  0.002  0.002  0.002  1.0
  Fe  Fe20  1  0.493  0.493  0.493  1.0
  H  H21  1  0.689  0.689  0.689  1.0
  O  O22  1  0.872  0.872  0.872  1.0
  O  O23  1  0.866  0.132  0.132  1.0
  O  O24  1  0.132  0.132  0.866  1.0
  O  O25  1  0.132  0.866  0.132  1.0
  O  O26  1  0.386  0.887  0.887  1.0
  O  O27  1  0.887  0.386  0.887  1.0
  O  O28  1  0.887  0.887  0.386  1.0
  O  O29  1  0.382  0.112  0.112  1.0
  O  O30  1  0.882  0.619  0.114  1.0
  O  O31  1  0.882  0.114  0.619  1.0
  O  O32  1  0.619  0.114  0.882  1.0
  O  O33  1  0.114  0.619  0.882  1.0
  O  O34  1  0.112  0.112  0.382  1.0
  O  O35  1  0.619  0.882  0.114  1.0
  O  O36  1  0.112  0.382  0.112  1.0
  O  O37  1  0.114  0.882  0.619  1.0
  O  O38  1  0.883  0.360  0.360  1.0
  O  O39  1  0.360  0.883  0.360  1.0
  O  O40  1  0.360  0.360  0.883  1.0
  O  O41  1  0.859  0.642  0.642  1.0
  O  O42  1  0.363  0.100  0.635  1.0
  O  O43  1  0.363  0.635  0.100  1.0
  O  O44  1  0.100  0.635  0.363  1.0
  O  O45  1  0.635  0.100  0.363  1.0
  O  O46  1  0.642  0.642  0.859  1.0
  O  O47  1  0.100  0.363  0.635  1.0
  O  O48  1  0.642  0.859  0.642  1.0
  O  O49  1  0.635  0.363  0.100  1.0
  O  O50  1  0.368  0.368  0.368  1.0
  O  O51  1  0.376  0.627  0.627  1.0
  O  O52  1  0.627  0.627  0.376  1.0
  O  O53  1  0.627  0.376  0.627  1.0
[/CIF]
.
The structure described by Fe21HO32 crystallizes in the trigonal R3m space group. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(4), two equivalent O(5), and two equivalent O(8) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(5)O4 tetrahedra,  a cornercorner with one Fe(7)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, corners with two equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with four equivalent Fe(3)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(3), two equivalent O(5), and two equivalent O(7) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(7)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, corners with three equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form FeO6 octahedra that share  a cornercorner with one Fe(5)O4 tetrahedra,  a cornercorner with one Fe(7)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, corners with two equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(6), one O(7), and two equivalent O(8) atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-59°. In the fifth Fe site, Fe(5) is bonded to one O(9) and three equivalent O(4) atoms to form FeO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with six equivalent Fe(3)O6 octahedra, and  a cornercorner with one Fe(8)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-64°. In the sixth Fe site, Fe(6) is bonded to one O(10), one O(3), and two equivalent O(5) atoms to form FeO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, corners with four equivalent Fe(3)O6 octahedra, and  a cornercorner with one Fe(8)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-62°. In the seventh Fe site, Fe(7) is bonded to one O(1) and three equivalent O(2) atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-56°. In the eighth Fe site, Fe(8) is bonded to one O(9) and three equivalent O(10) atoms to form corner-sharing FeO4 tetrahedra. H(1) is bonded in a trigonal non-coplanar geometry to three equivalent O(7) atoms. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Fe(7) and three equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(7), and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Fe(2), one Fe(6), and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded to one Fe(1), one Fe(5), and two equivalent Fe(3) atoms to form distorted corner-sharing OFe4 trigonal pyramids. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(2), one Fe(3), and one Fe(6) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(3) atoms. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Fe(4), two equivalent Fe(2), and one H(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(4) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Fe(5) and one Fe(8) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Fe(6) and one Fe(8) atom. is represented by the CIF card [CIF]
data_Fe21HO32
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.531
_cell_length_b   8.531
_cell_length_c   8.531
_cell_angle_alpha   89.297
_cell_angle_beta   89.297
_cell_angle_gamma   89.297
_symmetry_Int_Tables_number   1
_cell_volume   620.774
_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
  Fe  Fe0  1  0.616  0.133  0.133  1.0
  Fe  Fe1  1  0.133  0.616  0.133  1.0
  Fe  Fe2  1  0.133  0.133  0.616  1.0
  Fe  Fe3  1  0.624  0.877  0.877  1.0
  Fe  Fe4  1  0.131  0.380  0.865  1.0
  Fe  Fe5  1  0.131  0.865  0.380  1.0
  Fe  Fe6  1  0.380  0.865  0.131  1.0
  Fe  Fe7  1  0.865  0.380  0.131  1.0
  Fe  Fe8  1  0.877  0.877  0.624  1.0
  Fe  Fe9  1  0.380  0.131  0.865  1.0
  Fe  Fe10  1  0.877  0.624  0.877  1.0
  Fe  Fe11  1  0.865  0.131  0.380  1.0
  Fe  Fe12  1  0.501  0.981  0.501  1.0
  Fe  Fe13  1  0.501  0.501  0.981  1.0
  Fe  Fe14  1  0.981  0.501  0.501  1.0
  Fe  Fe15  1  0.249  0.249  0.249  1.0
  Fe  Fe16  1  0.258  0.750  0.750  1.0
  Fe  Fe17  1  0.750  0.750  0.258  1.0
  Fe  Fe18  1  0.750  0.258  0.750  1.0
  Fe  Fe19  1  0.002  0.002  0.002  1.0
  Fe  Fe20  1  0.493  0.493  0.493  1.0
  H  H21  1  0.689  0.689  0.689  1.0
  O  O22  1  0.872  0.872  0.872  1.0
  O  O23  1  0.866  0.132  0.132  1.0
  O  O24  1  0.132  0.132  0.866  1.0
  O  O25  1  0.132  0.866  0.132  1.0
  O  O26  1  0.386  0.887  0.887  1.0
  O  O27  1  0.887  0.386  0.887  1.0
  O  O28  1  0.887  0.887  0.386  1.0
  O  O29  1  0.382  0.112  0.112  1.0
  O  O30  1  0.882  0.619  0.114  1.0
  O  O31  1  0.882  0.114  0.619  1.0
  O  O32  1  0.619  0.114  0.882  1.0
  O  O33  1  0.114  0.619  0.882  1.0
  O  O34  1  0.112  0.112  0.382  1.0
  O  O35  1  0.619  0.882  0.114  1.0
  O  O36  1  0.112  0.382  0.112  1.0
  O  O37  1  0.114  0.882  0.619  1.0
  O  O38  1  0.883  0.360  0.360  1.0
  O  O39  1  0.360  0.883  0.360  1.0
  O  O40  1  0.360  0.360  0.883  1.0
  O  O41  1  0.859  0.642  0.642  1.0
  O  O42  1  0.363  0.100  0.635  1.0
  O  O43  1  0.363  0.635  0.100  1.0
  O  O44  1  0.100  0.635  0.363  1.0
  O  O45  1  0.635  0.100  0.363  1.0
  O  O46  1  0.642  0.642  0.859  1.0
  O  O47  1  0.100  0.363  0.635  1.0
  O  O48  1  0.642  0.859  0.642  1.0
  O  O49  1  0.635  0.363  0.100  1.0
  O  O50  1  0.368  0.368  0.368  1.0
  O  O51  1  0.376  0.627  0.627  1.0
  O  O52  1  0.627  0.627  0.376  1.0
  O  O53  1  0.627  0.376  0.627  1.0
[/CIF]
.