Materials Data on CaH2I2O7 by Materials Project
CaH2O7I2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.66 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to one Ca2+ and one I5+ atom. The O–I bond length is 1.82 Å. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+ and one I5+ atom. The O–I bond length is 1.83 Å. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and one I5+ atom. The O–I bond length is 1.84 Å. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Ca2+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca2+ and one I5+ atom. The O–I bond length is 1.84 Å. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and one I5+ atom. The O–I bond length is 1.82 Å. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and one I5+ atom. The O–I bond length is 1.84 Å. There are two inequivalent I5+ sites. In the first I5+ site, I5+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. In the second I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms.