DOI: 10.17188/1725521
title: Materials Data on Na2CrH5C4O11 by Materials Project

description: Na2CrH3(C2O5)2H2O crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional and consists of four water molecules and one Na2CrH3(C2O5)2 framework. In the Na2CrH3(C2O5)2 framework, there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to seven O2- atoms to form distorted NaO7 pentagonal bipyramids that share corners with two equivalent NaO5 trigonal bipyramids, edges with two equivalent CrO6 octahedra, and an edgeedge with one NaO7 pentagonal bipyramid. There are a spread of Na–O bond distances ranging from 2.48–2.73 Å. In the second Na1+ site, Na1+ is bonded to five O2- atoms to form distorted NaO5 trigonal bipyramids that share a cornercorner with one CrO6 octahedra and corners with two equivalent NaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 61°. There are a spread of Na–O bond distances ranging from 2.38–2.48 Å. Cr3+ is bonded to six O2- atoms to form CrO6 octahedra that share a cornercorner with one NaO5 trigonal bipyramid, an edgeedge with one CrO6 octahedra, and edges with two equivalent NaO7 pentagonal bipyramids. There are a spread of Cr–O bond distances ranging from 2.01–2.04 Å. There are four inequivalent C3+ sites. In the first C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.30 Å) C–O bond length. In the second C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.25 Å) and one longer (1.29 Å) C–O bond length. In the third C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.30 Å) C–O bond length. In the fourth C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.25 Å) and one longer (1.30 Å) C–O bond length. There are three 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 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Na1+, two equivalent Cr3+, and one H1+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Cr3+, and one C3+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr3+ and one C3+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Cr3+, and one C3+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Cr3+, and one C3+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Na1+ and one C3+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Na1+ and one C3+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Na1+ and one C3+ atom. In the tenth O2- site, O2- is bonded in a distorted single-bond geometry to two Na1+ and one C3+ atom.