Materials Data on CaH4Se2O7 by Materials Project
CaH4Se2O7 crystallizes in the triclinic P-1 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 2.41–2.62 Å. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.05 Å) and one longer (1.55 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.65 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.74 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are two inequivalent Se4+ sites. In the first Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.69–1.83 Å. In the second Se4+ site, Se4+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.71–1.83 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one Se4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one Se4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one H1+, and one Se4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one H1+, and one Se4+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ca2+, one H1+, and one Se4+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one Ca2+, one H1+, and one Se4+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three H1+ atoms.