Materials Data on Li2Cr2H4O9 by Materials Project
Li2Cr2H4O9 crystallizes in the monoclinic Cc space group. The structure is one-dimensional and consists of two Li2Cr2H4O9 ribbons oriented in the (0, 0, 1) direction. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.92–2.08 Å. In the second Li1+ site, Li1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Li–O bond distances ranging from 1.94–2.04 Å. There are two inequivalent Cr6+ sites. In the first Cr6+ site, Cr6+ is bonded to four O2- atoms to form corner-sharing CrO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.61–1.82 Å. In the second Cr6+ site, Cr6+ is bonded to four O2- atoms to form corner-sharing CrO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.62–1.77 Å. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.69 Å) H–O bond length. 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. In the third 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 fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two Cr6+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Cr6+, and one H1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Cr6+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one Cr6+ atom. In the fifth O2- site, O2- is bonded in a distorted T-shaped geometry to two Li1+ and one Cr6+ atom. In the sixth O2- site, O2- is bonded in a single-bond geometry to one Cr6+ atom. In the seventh O2- site, O2- is bonded in an L-shaped geometry to one Li1+ and one Cr6+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to two Li1+ and two H1+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Li1+ and two H1+ atoms.