The material described by (CaH4(CO3)2)8O2 crystallizes in the tetragonal I4 space group. The structure consists of two water atoms inside a CaH4(CO3)2 framework. In the CaH4(CO3)2 framework, Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(5) atom. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(4) and one O(6) atom. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(1) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(2) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(2) atom. There are six inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one C(1) atom. In the second O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one C(2) atom. In the third O site, O(5) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(1) atom. In the fourth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(2) atom. In the fifth O site, O(1) is bonded in a distorted water-like geometry to one Ca(1), one H(1), and one H(2) atom. In the sixth O site, O(2) is bonded in a distorted water-like geometry to one Ca(1), one H(3), and one H(4) atom. is represented by the CIF file [CIF]
data_Ca4H16C8O25
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.650
_cell_length_b   9.650
_cell_length_c   9.650
_cell_angle_alpha   98.355
_cell_angle_beta   98.355
_cell_angle_gamma   135.186
_symmetry_Int_Tables_number   1
_cell_volume   585.586
_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
  Ca  Ca0  1  0.299  0.202  0.503  1.0
  Ca  Ca1  1  0.699  0.797  0.497  1.0
  Ca  Ca2  1  0.202  0.699  0.903  1.0
  Ca  Ca3  1  0.797  0.299  0.097  1.0
  H  H4  1  0.182  0.274  0.241  1.0
  H  H5  1  0.032  0.941  0.759  1.0
  H  H6  1  0.274  0.032  0.091  1.0
  H  H7  1  0.941  0.182  0.909  1.0
  H  H8  1  0.820  0.724  0.755  1.0
  H  H9  1  0.969  0.066  0.245  1.0
  H  H10  1  0.724  0.969  0.903  1.0
  H  H11  1  0.066  0.820  0.097  1.0
  H  H12  1  0.247  0.882  0.341  1.0
  H  H13  1  0.541  0.906  0.659  1.0
  H  H14  1  0.882  0.541  0.635  1.0
  H  H15  1  0.906  0.247  0.365  1.0
  H  H16  1  0.757  0.118  0.661  1.0
  H  H17  1  0.458  0.096  0.339  1.0
  H  H18  1  0.118  0.458  0.362  1.0
  H  H19  1  0.096  0.757  0.638  1.0
  C  C20  1  0.657  0.349  0.795  1.0
  C  C21  1  0.554  0.862  0.205  1.0
  C  C22  1  0.349  0.554  0.692  1.0
  C  C23  1  0.862  0.657  0.308  1.0
  C  C24  1  0.341  0.651  0.206  1.0
  C  C25  1  0.445  0.135  0.794  1.0
  C  C26  1  0.651  0.445  0.310  1.0
  C  C27  1  0.135  0.341  0.690  1.0
  O  O28  1  0.116  0.147  0.265  1.0
  O  O29  1  0.883  0.852  0.735  1.0
  O  O30  1  0.147  0.883  0.031  1.0
  O  O31  1  0.852  0.116  0.969  1.0
  O  O32  1  0.378  0.029  0.405  1.0
  O  O33  1  0.624  0.973  0.595  1.0
  O  O34  1  0.029  0.624  0.651  1.0
  O  O35  1  0.973  0.378  0.349  1.0
  O  O36  1  0.646  0.422  0.701  1.0
  O  O37  1  0.722  0.945  0.299  1.0
  O  O38  1  0.422  0.722  0.777  1.0
  O  O39  1  0.945  0.646  0.223  1.0
  O  O40  1  0.353  0.581  0.304  1.0
  O  O41  1  0.278  0.049  0.696  1.0
  O  O42  1  0.581  0.278  0.229  1.0
  O  O43  1  0.049  0.353  0.771  1.0
  O  O44  1  0.824  0.429  0.888  1.0
  O  O45  1  0.541  0.936  0.112  1.0
  O  O46  1  0.429  0.541  0.605  1.0
  O  O47  1  0.936  0.824  0.395  1.0
  O  O48  1  0.175  0.572  0.113  1.0
  O  O49  1  0.459  0.063  0.887  1.0
  O  O50  1  0.572  0.459  0.396  1.0
  O  O51  1  0.063  0.175  0.604  1.0
  O  O52  1  0.349  0.349  0.000  1.0
[/CIF]
.
The material described by (CaH4(CO3)2)8O2 crystallizes in the tetragonal I4 space group. The structure consists of two water atoms inside a CaH4(CO3)2 framework. In the CaH4(CO3)2 framework, Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(5) atom. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(4) and one O(6) atom. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(1) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(2) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(2) atom. There are six inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one C(1) atom. In the second O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one C(2) atom. In the third O site, O(5) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(1) atom. In the fourth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(2) atom. In the fifth O site, O(1) is bonded in a distorted water-like geometry to one Ca(1), one H(1), and one H(2) atom. In the sixth O site, O(2) is bonded in a distorted water-like geometry to one Ca(1), one H(3), and one H(4) atom. is represented by the CIF file [CIF]
data_Ca4H16C8O25
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.650
_cell_length_b   9.650
_cell_length_c   9.650
_cell_angle_alpha   98.355
_cell_angle_beta   98.355
_cell_angle_gamma   135.186
_symmetry_Int_Tables_number   1
_cell_volume   585.586
_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
  Ca  Ca0  1  0.299  0.202  0.503  1.0
  Ca  Ca1  1  0.699  0.797  0.497  1.0
  Ca  Ca2  1  0.202  0.699  0.903  1.0
  Ca  Ca3  1  0.797  0.299  0.097  1.0
  H  H4  1  0.182  0.274  0.241  1.0
  H  H5  1  0.032  0.941  0.759  1.0
  H  H6  1  0.274  0.032  0.091  1.0
  H  H7  1  0.941  0.182  0.909  1.0
  H  H8  1  0.820  0.724  0.755  1.0
  H  H9  1  0.969  0.066  0.245  1.0
  H  H10  1  0.724  0.969  0.903  1.0
  H  H11  1  0.066  0.820  0.097  1.0
  H  H12  1  0.247  0.882  0.341  1.0
  H  H13  1  0.541  0.906  0.659  1.0
  H  H14  1  0.882  0.541  0.635  1.0
  H  H15  1  0.906  0.247  0.365  1.0
  H  H16  1  0.757  0.118  0.661  1.0
  H  H17  1  0.458  0.096  0.339  1.0
  H  H18  1  0.118  0.458  0.362  1.0
  H  H19  1  0.096  0.757  0.638  1.0
  C  C20  1  0.657  0.349  0.795  1.0
  C  C21  1  0.554  0.862  0.205  1.0
  C  C22  1  0.349  0.554  0.692  1.0
  C  C23  1  0.862  0.657  0.308  1.0
  C  C24  1  0.341  0.651  0.206  1.0
  C  C25  1  0.445  0.135  0.794  1.0
  C  C26  1  0.651  0.445  0.310  1.0
  C  C27  1  0.135  0.341  0.690  1.0
  O  O28  1  0.116  0.147  0.265  1.0
  O  O29  1  0.883  0.852  0.735  1.0
  O  O30  1  0.147  0.883  0.031  1.0
  O  O31  1  0.852  0.116  0.969  1.0
  O  O32  1  0.378  0.029  0.405  1.0
  O  O33  1  0.624  0.973  0.595  1.0
  O  O34  1  0.029  0.624  0.651  1.0
  O  O35  1  0.973  0.378  0.349  1.0
  O  O36  1  0.646  0.422  0.701  1.0
  O  O37  1  0.722  0.945  0.299  1.0
  O  O38  1  0.422  0.722  0.777  1.0
  O  O39  1  0.945  0.646  0.223  1.0
  O  O40  1  0.353  0.581  0.304  1.0
  O  O41  1  0.278  0.049  0.696  1.0
  O  O42  1  0.581  0.278  0.229  1.0
  O  O43  1  0.049  0.353  0.771  1.0
  O  O44  1  0.824  0.429  0.888  1.0
  O  O45  1  0.541  0.936  0.112  1.0
  O  O46  1  0.429  0.541  0.605  1.0
  O  O47  1  0.936  0.824  0.395  1.0
  O  O48  1  0.175  0.572  0.113  1.0
  O  O49  1  0.459  0.063  0.887  1.0
  O  O50  1  0.572  0.459  0.396  1.0
  O  O51  1  0.063  0.175  0.604  1.0
  O  O52  1  0.349  0.349  0.000  1.0
[/CIF]
.