CaH2O7I2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and two equivalent O(1) atoms. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(7) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(7) atom. There are seven inequivalent O sites. In the first O site, O(4) is bonded in a linear geometry to one Ca(1) and one I(2) atom. In the second O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one I(2) atom. In the third O site, O(6) is bonded in a bent 120 degrees geometry to one Ca(1) and one I(2) atom. In the fourth O site, O(7) is bonded in a distorted water-like geometry to one Ca(1), one H(1), and one H(2) atom. In the fifth O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca(1) and one I(1) atom. In the sixth O site, O(2) is bonded in a bent 120 degrees geometry to one Ca(1) and one I(1) atom. In the seventh O site, O(3) is bonded in a bent 120 degrees geometry to one Ca(1) and one I(1) atom. There are two inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. In the second I site, I(2) is bonded in a distorted trigonal non-coplanar geometry to one O(4), one O(5), and one O(6) atom.
CaH2O7I2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and two equivalent O(1) atoms. The Ca(1)-O(2) bond length is 2.47 Å. The Ca(1)-O(3) bond length is 2.52 Å. The Ca(1)-O(4) bond length is 2.35 Å. The Ca(1)-O(5) bond length is 2.66 Å. The Ca(1)-O(6) bond length is 2.44 Å. The Ca(1)-O(7) bond length is 2.52 Å. There is one shorter (2.53 Å) and one longer (2.64 Å) Ca(1)-O(1) bond length. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(7) atom. The H(1)-O(7) bond length is 0.98 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(7) atom. The H(2)-O(7) bond length is 0.98 Å. There are seven inequivalent O sites. In the first O site, O(4) is bonded in a linear geometry to one Ca(1) and one I(2) atom. The O(4)-I(2) bond length is 1.82 Å. In the second O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one I(2) atom. The O(5)-I(2) bond length is 1.83 Å. In the third O site, O(6) is bonded in a bent 120 degrees geometry to one Ca(1) and one I(2) atom. The O(6)-I(2) bond length is 1.84 Å. In the fourth O site, O(7) is bonded in a distorted water-like geometry to one Ca(1), one H(1), and one H(2) atom. In the fifth O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca(1) and one I(1) atom. The O(1)-I(1) bond length is 1.84 Å. In the sixth O site, O(2) is bonded in a bent 120 degrees geometry to one Ca(1) and one I(1) atom. The O(2)-I(1) bond length is 1.82 Å. In the seventh O site, O(3) is bonded in a bent 120 degrees geometry to one Ca(1) and one I(1) atom. The O(3)-I(1) bond length is 1.84 Å. There are two inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. In the second I site, I(2) is bonded in a distorted trigonal non-coplanar geometry to one O(4), one O(5), and one O(6) atom.