Materials Data on Cr3HO8 by Materials Project
HCr3O8 crystallizes in the monoclinic P2_1/m space group. The structure is two-dimensional and consists of one HCr3O8 sheet oriented in the (1, 0, 1) direction. there are three inequivalent Cr5+ sites. In the first Cr5+ site, Cr5+ is bonded to five O2- atoms to form a mixture of distorted corner and edge-sharing CrO5 trigonal bipyramids. There are a spread of Cr–O bond distances ranging from 1.59–1.94 Å. In the second Cr5+ site, Cr5+ is bonded to five O2- atoms to form a mixture of distorted corner and edge-sharing CrO5 trigonal bipyramids. There are a spread of Cr–O bond distances ranging from 1.74–1.94 Å. In the third Cr5+ site, Cr5+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Cr–O bond distances ranging from 1.59–1.97 Å. H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.46 Å) H–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to three Cr5+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one Cr5+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Cr5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr5+ and one H1+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr5+ and one H1+ atom. In the sixth O2- site, O2- is bonded in a distorted T-shaped geometry to three Cr5+ atoms. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two Cr5+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Cr5+ atoms.