The material structure described by CaCO3 is Calcite-like structured and crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing CaO6 octahedra. The corner-sharing octahedral tilt angles range from 61-64°. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one C(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Ca(1) and one C(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Ca(1) and one C(1) atom. is represented by the CIF card [CIF]
data_CaCO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.029
_cell_length_b   6.342
_cell_length_c   8.035
_cell_angle_alpha   72.941
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   244.959
_cell_formula_units_Z   4
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  0.754  0.757  0.734  1.0
  Ca  Ca1  1  0.746  0.757  0.234  1.0
  Ca  Ca2  1  0.254  0.243  0.766  1.0
  Ca  Ca3  1  0.246  0.243  0.266  1.0
  C  C4  1  0.253  0.746  0.999  1.0
  C  C5  1  0.747  0.254  0.001  1.0
  C  C6  1  0.247  0.746  0.499  1.0
  C  C7  1  0.753  0.254  0.501  1.0
  O  O8  1  0.899  0.128  0.623  1.0
  O  O9  1  0.101  0.872  0.377  1.0
  O  O10  1  0.637  0.386  0.866  1.0
  O  O11  1  0.137  0.614  0.634  1.0
  O  O12  1  0.503  0.757  0.486  1.0
  O  O13  1  0.003  0.243  0.014  1.0
  O  O14  1  0.399  0.872  0.877  1.0
  O  O15  1  0.497  0.243  0.514  1.0
  O  O16  1  0.601  0.128  0.123  1.0
  O  O17  1  0.863  0.386  0.366  1.0
  O  O18  1  0.997  0.757  0.986  1.0
  O  O19  1  0.363  0.614  0.134  1.0
[/CIF]
.
The material structure described by CaCO3 is Calcite-like structured and crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing CaO6 octahedra. The corner-sharing octahedral tilt angles range from 61-64°. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one C(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Ca(1) and one C(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Ca(1) and one C(1) atom. is represented by the CIF card [CIF]
data_CaCO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.029
_cell_length_b   6.342
_cell_length_c   8.035
_cell_angle_alpha   72.941
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   244.959
_cell_formula_units_Z   4
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  0.754  0.757  0.734  1.0
  Ca  Ca1  1  0.746  0.757  0.234  1.0
  Ca  Ca2  1  0.254  0.243  0.766  1.0
  Ca  Ca3  1  0.246  0.243  0.266  1.0
  C  C4  1  0.253  0.746  0.999  1.0
  C  C5  1  0.747  0.254  0.001  1.0
  C  C6  1  0.247  0.746  0.499  1.0
  C  C7  1  0.753  0.254  0.501  1.0
  O  O8  1  0.899  0.128  0.623  1.0
  O  O9  1  0.101  0.872  0.377  1.0
  O  O10  1  0.637  0.386  0.866  1.0
  O  O11  1  0.137  0.614  0.634  1.0
  O  O12  1  0.503  0.757  0.486  1.0
  O  O13  1  0.003  0.243  0.014  1.0
  O  O14  1  0.399  0.872  0.877  1.0
  O  O15  1  0.497  0.243  0.514  1.0
  O  O16  1  0.601  0.128  0.123  1.0
  O  O17  1  0.863  0.386  0.366  1.0
  O  O18  1  0.997  0.757  0.986  1.0
  O  O19  1  0.363  0.614  0.134  1.0
[/CIF]
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