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.
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. There is one shorter (2.47 Å) and one longer (2.49 Å) Ca(1)-O(1) bond length. Both Ca(1)-O(2) bond lengths are 2.50 Å. There is one shorter (2.49 Å) and one longer (2.53 Å) Ca(1)-O(3) bond length. There is one shorter (2.43 Å) and one longer (2.49 Å) Ca(1)-O(4) bond length. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(4) atom. The C(1)-O(1) bond length is 1.31 Å. The C(1)-O(2) bond length is 1.31 Å. The C(1)-O(4) bond length is 1.28 Å. 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. The H(1)-O(3) bond length is 1.00 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(3) atom. The H(2)-O(3) bond length is 1.00 Å. 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.