The material structure described by CaCO3.H2O crystallizes in the trigonal P3_1 space group. Ca(1) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of distorted edge and corner-sharing CaO8 hexagonal bipyramids. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(4) atom. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(3) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to two equivalent Ca(1), one H(1), and one H(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(1) atom. is represented by the CIF card [CIF]
data_CaH2CO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.148
_cell_length_b   6.148
_cell_length_c   7.578
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   248.022
_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  0.724  0.725  0.664  1.0
  Ca  Ca1  1  0.275  0.999  0.998  1.0
  Ca  Ca2  1  0.001  0.276  0.331  1.0
  H  H3  1  0.546  0.449  0.246  1.0
  H  H4  1  0.551  0.097  0.579  1.0
  H  H5  1  0.903  0.454  0.912  1.0
  H  H6  1  0.459  0.908  0.418  1.0
  H  H7  1  0.092  0.550  0.751  1.0
  H  H8  1  0.450  0.541  0.084  1.0
  C  C9  1  0.255  0.279  0.703  1.0
  C  C10  1  0.721  0.977  0.036  1.0
  C  C11  1  0.023  0.745  0.370  1.0
  O  O12  1  0.812  0.538  0.402  1.0
  O  O13  1  0.462  0.274  0.736  1.0
  O  O14  1  0.726  0.188  0.069  1.0
  O  O15  1  0.190  0.734  0.267  1.0
  O  O16  1  0.266  0.455  0.600  1.0
  O  O17  1  0.545  0.810  0.933  1.0
  O  O18  1  0.397  0.398  0.168  1.0
  O  O19  1  0.602  0.999  0.501  1.0
  O  O20  1  0.001  0.603  0.834  1.0
  O  O21  1  0.878  0.929  0.115  1.0
  O  O22  1  0.071  0.949  0.448  1.0
  O  O23  1  0.051  0.122  0.782  1.0
[/CIF]
.
The material structure described by CaCO3.H2O crystallizes in the trigonal P3_1 space group. Ca(1) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of distorted edge and corner-sharing CaO8 hexagonal bipyramids. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(4) atom. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(3) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to two equivalent Ca(1), one H(1), and one H(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(1) atom. is represented by the CIF card [CIF]
data_CaH2CO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.148
_cell_length_b   6.148
_cell_length_c   7.578
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   248.022
_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  0.724  0.725  0.664  1.0
  Ca  Ca1  1  0.275  0.999  0.998  1.0
  Ca  Ca2  1  0.001  0.276  0.331  1.0
  H  H3  1  0.546  0.449  0.246  1.0
  H  H4  1  0.551  0.097  0.579  1.0
  H  H5  1  0.903  0.454  0.912  1.0
  H  H6  1  0.459  0.908  0.418  1.0
  H  H7  1  0.092  0.550  0.751  1.0
  H  H8  1  0.450  0.541  0.084  1.0
  C  C9  1  0.255  0.279  0.703  1.0
  C  C10  1  0.721  0.977  0.036  1.0
  C  C11  1  0.023  0.745  0.370  1.0
  O  O12  1  0.812  0.538  0.402  1.0
  O  O13  1  0.462  0.274  0.736  1.0
  O  O14  1  0.726  0.188  0.069  1.0
  O  O15  1  0.190  0.734  0.267  1.0
  O  O16  1  0.266  0.455  0.600  1.0
  O  O17  1  0.545  0.810  0.933  1.0
  O  O18  1  0.397  0.398  0.168  1.0
  O  O19  1  0.602  0.999  0.501  1.0
  O  O20  1  0.001  0.603  0.834  1.0
  O  O21  1  0.878  0.929  0.115  1.0
  O  O22  1  0.071  0.949  0.448  1.0
  O  O23  1  0.051  0.122  0.782  1.0
[/CIF]
.