The crystal structure described by K2CaH2S2O9 crystallizes in the monoclinic P2_1/m space group. K(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(6), one O(7), two equivalent O(4), and two equivalent O(5) atoms. Ca(1) is bonded in a 9-coordinate geometry to one O(1), one O(3), one O(7), two equivalent O(6), and four equivalent O(2) atoms. H(1) is bonded in a single-bond geometry to one O(1) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded in a tetrahedral geometry to one O(4), one O(5), and two equivalent O(6) atoms. In the second S site, S(2) is bonded in a tetrahedral geometry to one O(3), one O(7), and two equivalent O(2) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to two equivalent K(1), one Ca(1), and two equivalent H(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one S(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(1), one Ca(1), and one S(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to four equivalent K(1) and one S(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to four equivalent K(1) and one S(1) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one K(1), one Ca(1), and one S(1) atom. In the seventh O site, O(7) is bonded in a distorted tetrahedral geometry to two equivalent K(1), one Ca(1), and one S(2) atom. is represented by the CIF card [CIF]
data_K2CaH2S2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.213
_cell_length_b   6.335
_cell_length_c   9.925
_cell_angle_alpha   76.389
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   440.786
_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  0.505  0.815  0.334  1.0
  K  K1  1  0.005  0.185  0.666  1.0
  K  K2  1  0.495  0.185  0.666  1.0
  K  K3  1  0.995  0.815  0.334  1.0
  Ca  Ca4  1  0.750  0.665  0.968  1.0
  Ca  Ca5  1  0.250  0.335  0.032  1.0
  H  H6  1  0.139  0.590  0.751  1.0
  H  H7  1  0.639  0.410  0.249  1.0
  H  H8  1  0.861  0.410  0.249  1.0
  H  H9  1  0.361  0.590  0.751  1.0
  S  S10  1  0.750  0.719  0.641  1.0
  S  S11  1  0.250  0.281  0.359  1.0
  S  S12  1  0.750  0.160  0.992  1.0
  S  S13  1  0.250  0.840  0.008  1.0
  O  O14  1  0.750  0.504  0.223  1.0
  O  O15  1  0.250  0.496  0.777  1.0
  O  O16  1  0.416  0.696  0.017  1.0
  O  O17  1  0.916  0.304  0.983  1.0
  O  O18  1  0.584  0.304  0.983  1.0
  O  O19  1  0.084  0.696  0.017  1.0
  O  O20  1  0.250  0.015  0.879  1.0
  O  O21  1  0.750  0.985  0.121  1.0
  O  O22  1  0.250  0.069  0.465  1.0
  O  O23  1  0.750  0.931  0.535  1.0
  O  O24  1  0.250  0.463  0.430  1.0
  O  O25  1  0.750  0.537  0.570  1.0
  O  O26  1  0.084  0.292  0.267  1.0
  O  O27  1  0.584  0.708  0.733  1.0
  O  O28  1  0.916  0.708  0.733  1.0
  O  O29  1  0.416  0.292  0.267  1.0
  O  O30  1  0.250  0.946  0.128  1.0
  O  O31  1  0.750  0.054  0.872  1.0
[/CIF]
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The crystal structure described by K2CaH2S2O9 crystallizes in the monoclinic P2_1/m space group. K(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(6), one O(7), two equivalent O(4), and two equivalent O(5) atoms. Ca(1) is bonded in a 9-coordinate geometry to one O(1), one O(3), one O(7), two equivalent O(6), and four equivalent O(2) atoms. H(1) is bonded in a single-bond geometry to one O(1) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded in a tetrahedral geometry to one O(4), one O(5), and two equivalent O(6) atoms. In the second S site, S(2) is bonded in a tetrahedral geometry to one O(3), one O(7), and two equivalent O(2) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to two equivalent K(1), one Ca(1), and two equivalent H(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one S(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(1), one Ca(1), and one S(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to four equivalent K(1) and one S(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to four equivalent K(1) and one S(1) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one K(1), one Ca(1), and one S(1) atom. In the seventh O site, O(7) is bonded in a distorted tetrahedral geometry to two equivalent K(1), one Ca(1), and one S(2) atom. is represented by the CIF card [CIF]
data_K2CaH2S2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.213
_cell_length_b   6.335
_cell_length_c   9.925
_cell_angle_alpha   76.389
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   440.786
_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  0.505  0.815  0.334  1.0
  K  K1  1  0.005  0.185  0.666  1.0
  K  K2  1  0.495  0.185  0.666  1.0
  K  K3  1  0.995  0.815  0.334  1.0
  Ca  Ca4  1  0.750  0.665  0.968  1.0
  Ca  Ca5  1  0.250  0.335  0.032  1.0
  H  H6  1  0.139  0.590  0.751  1.0
  H  H7  1  0.639  0.410  0.249  1.0
  H  H8  1  0.861  0.410  0.249  1.0
  H  H9  1  0.361  0.590  0.751  1.0
  S  S10  1  0.750  0.719  0.641  1.0
  S  S11  1  0.250  0.281  0.359  1.0
  S  S12  1  0.750  0.160  0.992  1.0
  S  S13  1  0.250  0.840  0.008  1.0
  O  O14  1  0.750  0.504  0.223  1.0
  O  O15  1  0.250  0.496  0.777  1.0
  O  O16  1  0.416  0.696  0.017  1.0
  O  O17  1  0.916  0.304  0.983  1.0
  O  O18  1  0.584  0.304  0.983  1.0
  O  O19  1  0.084  0.696  0.017  1.0
  O  O20  1  0.250  0.015  0.879  1.0
  O  O21  1  0.750  0.985  0.121  1.0
  O  O22  1  0.250  0.069  0.465  1.0
  O  O23  1  0.750  0.931  0.535  1.0
  O  O24  1  0.250  0.463  0.430  1.0
  O  O25  1  0.750  0.537  0.570  1.0
  O  O26  1  0.084  0.292  0.267  1.0
  O  O27  1  0.584  0.708  0.733  1.0
  O  O28  1  0.916  0.708  0.733  1.0
  O  O29  1  0.416  0.292  0.267  1.0
  O  O30  1  0.250  0.946  0.128  1.0
  O  O31  1  0.750  0.054  0.872  1.0
[/CIF]
.