The material structure described by K2FeH4(SO5)2 crystallizes in the triclinic P-1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one O(2), one O(4), one O(5), one O(7), one O(9), two equivalent O(1), and two equivalent O(3) atoms. In the second K site, K(2) is bonded in a 9-coordinate geometry to one H(3), one O(10), one O(4), one O(5), one O(7), two equivalent O(6), and two equivalent O(8) atoms. Fe(1) is bonded to one O(1), one O(10), one O(4), one O(5), one O(8), and one O(9) atom to form FeO6 octahedra that share corners with two equivalent S(1)O4 tetrahedra and corners with two equivalent S(2)O4 tetrahedra. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(9) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(6) and one O(9) atom. In the third H site, H(3) is bonded in a single-bond geometry to one K(2) and one O(10) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(10) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-45°. In the second S site, S(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form SO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-48°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one S(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1) and one S(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(1) and one S(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Fe(1), and one S(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Fe(1), and one S(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent K(2), one H(2), and one S(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one S(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to two equivalent K(2), one Fe(1), and one S(2) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one K(1), one Fe(1), one H(1), and one H(2) atom. In the tenth O site, O(10) is bonded in a distorted water-like geometry to one K(2), one Fe(1), one H(3), and one H(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2FeH4(SO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.572
_cell_length_b   7.466
_cell_length_c   10.800
_cell_angle_alpha   72.901
_cell_angle_beta   73.866
_cell_angle_gamma   69.755
_symmetry_Int_Tables_number   1
_cell_volume   465.907
_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  0.292  0.249  0.900  1.0
  K  K1  1  0.240  0.761  0.578  1.0
  K  K2  1  0.708  0.751  0.100  1.0
  K  K3  1  0.760  0.239  0.422  1.0
  Fe  Fe4  1  0.753  0.522  0.751  1.0
  Fe  Fe5  1  0.247  0.478  0.249  1.0
  H  H6  1  0.774  0.152  0.859  1.0
  H  H7  1  0.867  0.178  0.704  1.0
  H  H8  1  0.863  0.819  0.796  1.0
  H  H9  1  0.665  0.916  0.714  1.0
  H  H10  1  0.226  0.848  0.141  1.0
  H  H11  1  0.133  0.822  0.296  1.0
  H  H12  1  0.137  0.181  0.204  1.0
  H  H13  1  0.335  0.084  0.286  1.0
  S  S14  1  0.250  0.721  0.927  1.0
  S  S15  1  0.231  0.270  0.584  1.0
  S  S16  1  0.750  0.279  0.073  1.0
  S  S17  1  0.769  0.730  0.416  1.0
  O  O18  1  0.193  0.569  0.047  1.0
  O  O19  1  0.043  0.844  0.879  1.0
  O  O20  1  0.356  0.842  0.960  1.0
  O  O21  1  0.403  0.618  0.821  1.0
  O  O22  1  0.105  0.407  0.677  1.0
  O  O23  1  0.082  0.165  0.574  1.0
  O  O24  1  0.427  0.132  0.636  1.0
  O  O25  1  0.306  0.391  0.452  1.0
  O  O26  1  0.737  0.226  0.772  1.0
  O  O27  1  0.792  0.801  0.732  1.0
  O  O28  1  0.807  0.431  0.953  1.0
  O  O29  1  0.957  0.156  0.121  1.0
  O  O30  1  0.644  0.158  0.040  1.0
  O  O31  1  0.597  0.382  0.179  1.0
  O  O32  1  0.895  0.593  0.323  1.0
  O  O33  1  0.918  0.835  0.426  1.0
  O  O34  1  0.573  0.868  0.364  1.0
  O  O35  1  0.694  0.609  0.548  1.0
  O  O36  1  0.263  0.774  0.228  1.0
  O  O37  1  0.208  0.199  0.268  1.0
[/CIF]
.
The material structure described by K2FeH4(SO5)2 crystallizes in the triclinic P-1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one O(2), one O(4), one O(5), one O(7), one O(9), two equivalent O(1), and two equivalent O(3) atoms. In the second K site, K(2) is bonded in a 9-coordinate geometry to one H(3), one O(10), one O(4), one O(5), one O(7), two equivalent O(6), and two equivalent O(8) atoms. Fe(1) is bonded to one O(1), one O(10), one O(4), one O(5), one O(8), and one O(9) atom to form FeO6 octahedra that share corners with two equivalent S(1)O4 tetrahedra and corners with two equivalent S(2)O4 tetrahedra. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(9) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(6) and one O(9) atom. In the third H site, H(3) is bonded in a single-bond geometry to one K(2) and one O(10) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(10) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-45°. In the second S site, S(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form SO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-48°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one S(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1) and one S(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(1) and one S(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Fe(1), and one S(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Fe(1), and one S(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent K(2), one H(2), and one S(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one S(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to two equivalent K(2), one Fe(1), and one S(2) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one K(1), one Fe(1), one H(1), and one H(2) atom. In the tenth O site, O(10) is bonded in a distorted water-like geometry to one K(2), one Fe(1), one H(3), and one H(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2FeH4(SO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.572
_cell_length_b   7.466
_cell_length_c   10.800
_cell_angle_alpha   72.901
_cell_angle_beta   73.866
_cell_angle_gamma   69.755
_symmetry_Int_Tables_number   1
_cell_volume   465.907
_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  0.292  0.249  0.900  1.0
  K  K1  1  0.240  0.761  0.578  1.0
  K  K2  1  0.708  0.751  0.100  1.0
  K  K3  1  0.760  0.239  0.422  1.0
  Fe  Fe4  1  0.753  0.522  0.751  1.0
  Fe  Fe5  1  0.247  0.478  0.249  1.0
  H  H6  1  0.774  0.152  0.859  1.0
  H  H7  1  0.867  0.178  0.704  1.0
  H  H8  1  0.863  0.819  0.796  1.0
  H  H9  1  0.665  0.916  0.714  1.0
  H  H10  1  0.226  0.848  0.141  1.0
  H  H11  1  0.133  0.822  0.296  1.0
  H  H12  1  0.137  0.181  0.204  1.0
  H  H13  1  0.335  0.084  0.286  1.0
  S  S14  1  0.250  0.721  0.927  1.0
  S  S15  1  0.231  0.270  0.584  1.0
  S  S16  1  0.750  0.279  0.073  1.0
  S  S17  1  0.769  0.730  0.416  1.0
  O  O18  1  0.193  0.569  0.047  1.0
  O  O19  1  0.043  0.844  0.879  1.0
  O  O20  1  0.356  0.842  0.960  1.0
  O  O21  1  0.403  0.618  0.821  1.0
  O  O22  1  0.105  0.407  0.677  1.0
  O  O23  1  0.082  0.165  0.574  1.0
  O  O24  1  0.427  0.132  0.636  1.0
  O  O25  1  0.306  0.391  0.452  1.0
  O  O26  1  0.737  0.226  0.772  1.0
  O  O27  1  0.792  0.801  0.732  1.0
  O  O28  1  0.807  0.431  0.953  1.0
  O  O29  1  0.957  0.156  0.121  1.0
  O  O30  1  0.644  0.158  0.040  1.0
  O  O31  1  0.597  0.382  0.179  1.0
  O  O32  1  0.895  0.593  0.323  1.0
  O  O33  1  0.918  0.835  0.426  1.0
  O  O34  1  0.573  0.868  0.364  1.0
  O  O35  1  0.694  0.609  0.548  1.0
  O  O36  1  0.263  0.774  0.228  1.0
  O  O37  1  0.208  0.199  0.268  1.0
[/CIF]
.