Ca(O6I)2 crystallizes in the orthorhombic Fdd2 space group. Ca(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted CaO6 pentagonal pyramids that share edges with two equivalent I(1)O5 trigonal bipyramids. There are six inequivalent O sites. In the first O site, O(3) is bonded in a single-bond geometry to one I(1) atom. In the second O site, O(4) is bonded in a bent 150 degrees geometry to one Ca(1) and one O(6) atom. In the third O site, O(5) is bonded in an L-shaped geometry to one Ca(1) and one I(1) atom. In the fourth O site, O(6) is bonded in a single-bond geometry to one O(4) atom. In the fifth O site, O(1) is bonded in a water-like geometry to one Ca(1) and one I(1) atom. In the sixth O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent I(1) atoms. I(1) is bonded to one O(1), one O(3), one O(5), and two equivalent O(2) atoms to form IO5 trigonal bipyramids that share corners with two equivalent I(1)O5 trigonal bipyramids and  an edgeedge with one Ca(1)O6 pentagonal pyramid.
Ca(O6I)2 crystallizes in the orthorhombic Fdd2 space group. Ca(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted CaO6 pentagonal pyramids that share edges with two equivalent I(1)O5 trigonal bipyramids. Both Ca(1)-O(1) bond lengths are 2.43 Å. Both Ca(1)-O(4) bond lengths are 2.59 Å. Both Ca(1)-O(5) bond lengths are 2.46 Å. There are six inequivalent O sites. In the first O site, O(3) is bonded in a single-bond geometry to one I(1) atom. The O(3)-I(1) bond length is 1.80 Å. In the second O site, O(4) is bonded in a bent 150 degrees geometry to one Ca(1) and one O(6) atom. The O(4)-O(6) bond length is 1.23 Å. In the third O site, O(5) is bonded in an L-shaped geometry to one Ca(1) and one I(1) atom. The O(5)-I(1) bond length is 1.83 Å. In the fourth O site, O(6) is bonded in a single-bond geometry to one O(4) atom. In the fifth O site, O(1) is bonded in a water-like geometry to one Ca(1) and one I(1) atom. The O(1)-I(1) bond length is 1.81 Å. In the sixth O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent I(1) atoms. There is one shorter (1.96 Å) and one longer (2.07 Å) O(2)-I(1) bond length. I(1) is bonded to one O(1), one O(3), one O(5), and two equivalent O(2) atoms to form IO5 trigonal bipyramids that share corners with two equivalent I(1)O5 trigonal bipyramids and  an edgeedge with one Ca(1)O6 pentagonal pyramid.