The crystal structure described by Ca2H2S2O9 crystallizes in the monoclinic C2 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(10), two equivalent O(4), and two equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded in a 9-coordinate geometry to one O(10), one O(11), one O(13), one O(3), one O(4), two equivalent O(5), and two equivalent O(8) atoms. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(6), one O(7), two equivalent O(12), and two equivalent O(9) atoms. In the fourth Ca site, Ca(4) is bonded in a 9-coordinate geometry to one O(14), two equivalent O(11), two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(14) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(13) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(13) atom. There are three inequivalent S sites. In the first S site, S(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the second S site, S(2) is bonded in a tetrahedral geometry to one O(5), one O(6), one O(7), and one O(8) atom. In the third S site, S(3) is bonded in a tetrahedral geometry to one O(10), one O(11), one O(12), and one O(9) atom. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(3), and one S(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(3), one Ca(4), and one S(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ca(2), one Ca(4), and one S(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one S(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Ca(2) and one S(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ca(3), one Ca(4), and one S(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(3), and one S(2) atom. In the eighth O site, O(8) is bonded in a 1-coordinate geometry to two equivalent Ca(2) and one S(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to two equivalent Ca(3) and one S(3) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one S(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ca(2), one Ca(4), and one S(3) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca(3) and one S(3) atom. In the thirteenth O site, O(13) is bonded in a distorted water-like geometry to one Ca(2), one H(2), and one H(3) atom. In the fourteenth O site, O(14) is bonded in a distorted water-like geometry to one Ca(4) and two equivalent H(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2H2S2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.468
_cell_length_b   9.468
_cell_length_c   12.200
_cell_angle_alpha   50.411
_cell_angle_beta   50.411
_cell_angle_gamma   43.667
_symmetry_Int_Tables_number   1
_cell_volume   549.033
_cell_formula_units_Z   3
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
  Ca  Ca0  1  0.484  0.516  0.500  1.0
  Ca  Ca1  1  0.982  0.343  0.556  1.0
  Ca  Ca2  1  0.657  0.018  0.444  1.0
  Ca  Ca3  1  0.118  0.553  0.926  1.0
  Ca  Ca4  1  0.447  0.882  0.074  1.0
  Ca  Ca5  1  0.984  0.016  0.000  1.0
  H  H6  1  0.602  0.471  0.912  1.0
  H  H7  1  0.529  0.398  0.088  1.0
  H  H8  1  0.094  0.213  0.326  1.0
  H  H9  1  0.787  0.906  0.674  1.0
  H  H10  1  0.309  0.094  0.343  1.0
  H  H11  1  0.906  0.691  0.657  1.0
  S  S12  1  0.233  0.269  0.748  1.0
  S  S13  1  0.731  0.767  0.252  1.0
  S  S14  1  0.235  0.603  0.306  1.0
  S  S15  1  0.397  0.765  0.694  1.0
  S  S16  1  0.882  0.291  0.188  1.0
  S  S17  1  0.709  0.118  0.812  1.0
  O  O18  1  0.172  0.459  0.757  1.0
  O  O19  1  0.541  0.828  0.243  1.0
  O  O20  1  0.286  0.074  0.885  1.0
  O  O21  1  0.926  0.714  0.115  1.0
  O  O22  1  0.051  0.319  0.740  1.0
  O  O23  1  0.681  0.949  0.260  1.0
  O  O24  1  0.426  0.231  0.609  1.0
  O  O25  1  0.769  0.574  0.391  1.0
  O  O26  1  0.006  0.665  0.404  1.0
  O  O27  1  0.335  0.994  0.596  1.0
  O  O28  1  0.256  0.721  0.143  1.0
  O  O29  1  0.279  0.744  0.857  1.0
  O  O30  1  0.311  0.665  0.336  1.0
  O  O31  1  0.335  0.689  0.664  1.0
  O  O32  1  0.366  0.366  0.338  1.0
  O  O33  1  0.634  0.634  0.662  1.0
  O  O34  1  0.782  0.515  0.083  1.0
  O  O35  1  0.485  0.218  0.917  1.0
  O  O36  1  0.767  0.285  0.347  1.0
  O  O37  1  0.715  0.233  0.653  1.0
  O  O38  1  0.883  0.139  0.182  1.0
  O  O39  1  0.861  0.117  0.818  1.0
  O  O40  1  0.113  0.218  0.139  1.0
  O  O41  1  0.782  0.887  0.861  1.0
  O  O42  1  0.153  0.166  0.394  1.0
  O  O43  1  0.834  0.847  0.606  1.0
  O  O44  1  0.648  0.352  0.000  1.0
[/CIF]
.
The crystal structure described by Ca2H2S2O9 crystallizes in the monoclinic C2 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(10), two equivalent O(4), and two equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded in a 9-coordinate geometry to one O(10), one O(11), one O(13), one O(3), one O(4), two equivalent O(5), and two equivalent O(8) atoms. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(6), one O(7), two equivalent O(12), and two equivalent O(9) atoms. In the fourth Ca site, Ca(4) is bonded in a 9-coordinate geometry to one O(14), two equivalent O(11), two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(14) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(13) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(13) atom. There are three inequivalent S sites. In the first S site, S(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the second S site, S(2) is bonded in a tetrahedral geometry to one O(5), one O(6), one O(7), and one O(8) atom. In the third S site, S(3) is bonded in a tetrahedral geometry to one O(10), one O(11), one O(12), and one O(9) atom. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(3), and one S(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(3), one Ca(4), and one S(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ca(2), one Ca(4), and one S(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one S(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Ca(2) and one S(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ca(3), one Ca(4), and one S(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(3), and one S(2) atom. In the eighth O site, O(8) is bonded in a 1-coordinate geometry to two equivalent Ca(2) and one S(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to two equivalent Ca(3) and one S(3) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one S(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ca(2), one Ca(4), and one S(3) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca(3) and one S(3) atom. In the thirteenth O site, O(13) is bonded in a distorted water-like geometry to one Ca(2), one H(2), and one H(3) atom. In the fourteenth O site, O(14) is bonded in a distorted water-like geometry to one Ca(4) and two equivalent H(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2H2S2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.468
_cell_length_b   9.468
_cell_length_c   12.200
_cell_angle_alpha   50.411
_cell_angle_beta   50.411
_cell_angle_gamma   43.667
_symmetry_Int_Tables_number   1
_cell_volume   549.033
_cell_formula_units_Z   3
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
  Ca  Ca0  1  0.484  0.516  0.500  1.0
  Ca  Ca1  1  0.982  0.343  0.556  1.0
  Ca  Ca2  1  0.657  0.018  0.444  1.0
  Ca  Ca3  1  0.118  0.553  0.926  1.0
  Ca  Ca4  1  0.447  0.882  0.074  1.0
  Ca  Ca5  1  0.984  0.016  0.000  1.0
  H  H6  1  0.602  0.471  0.912  1.0
  H  H7  1  0.529  0.398  0.088  1.0
  H  H8  1  0.094  0.213  0.326  1.0
  H  H9  1  0.787  0.906  0.674  1.0
  H  H10  1  0.309  0.094  0.343  1.0
  H  H11  1  0.906  0.691  0.657  1.0
  S  S12  1  0.233  0.269  0.748  1.0
  S  S13  1  0.731  0.767  0.252  1.0
  S  S14  1  0.235  0.603  0.306  1.0
  S  S15  1  0.397  0.765  0.694  1.0
  S  S16  1  0.882  0.291  0.188  1.0
  S  S17  1  0.709  0.118  0.812  1.0
  O  O18  1  0.172  0.459  0.757  1.0
  O  O19  1  0.541  0.828  0.243  1.0
  O  O20  1  0.286  0.074  0.885  1.0
  O  O21  1  0.926  0.714  0.115  1.0
  O  O22  1  0.051  0.319  0.740  1.0
  O  O23  1  0.681  0.949  0.260  1.0
  O  O24  1  0.426  0.231  0.609  1.0
  O  O25  1  0.769  0.574  0.391  1.0
  O  O26  1  0.006  0.665  0.404  1.0
  O  O27  1  0.335  0.994  0.596  1.0
  O  O28  1  0.256  0.721  0.143  1.0
  O  O29  1  0.279  0.744  0.857  1.0
  O  O30  1  0.311  0.665  0.336  1.0
  O  O31  1  0.335  0.689  0.664  1.0
  O  O32  1  0.366  0.366  0.338  1.0
  O  O33  1  0.634  0.634  0.662  1.0
  O  O34  1  0.782  0.515  0.083  1.0
  O  O35  1  0.485  0.218  0.917  1.0
  O  O36  1  0.767  0.285  0.347  1.0
  O  O37  1  0.715  0.233  0.653  1.0
  O  O38  1  0.883  0.139  0.182  1.0
  O  O39  1  0.861  0.117  0.818  1.0
  O  O40  1  0.113  0.218  0.139  1.0
  O  O41  1  0.782  0.887  0.861  1.0
  O  O42  1  0.153  0.166  0.394  1.0
  O  O43  1  0.834  0.847  0.606  1.0
  O  O44  1  0.648  0.352  0.000  1.0
[/CIF]
.