DOE OSTI2020
CrN2O5CrN2O3 crystallizes in the monoclinic Pm space group. The structure is one-dimensional and consists of one CrN2O3 ribbon oriented in the (0, 1, 0) direction and one CrN2O5 ribbon oriented in the (0, 1, 0) direction. In the CrN2O3 ribbon, Cr6+ is bonded in a tetrahedral geometry to one N1+ and three O2- atoms. The Cr–N bond length is 1.55 Å. There is one shorter (1.61 Å) and two longer (1.98 Å) Cr–O bond length. There are two inequivalent N1+ sites. In the first N1+ site, N1+ is bonded in a water-like geometry to two equivalent O2- atoms. Both N–O bond lengths are 1.28 Å. In the second N1+ site, N1+ is bonded in a single-bond geometry to one Cr6+ atom. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr6+ and one N1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one Cr6+ atom. In the CrN2O5 ribbon, Cr6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Cr–O bond distances ranging from 1.60–1.92 Å. There are two inequivalent N1+ sites. In the first N1+ site, N1+ is bonded in a single-bond geometry to one O2- atom. The N–O bond length is 1.22 Å. In the second N1+ site, N1+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There is one shorter (1.15 Å) and two longer (2.02 Å) N–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one Cr6+ and one N1+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr6+ and one N1+ 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 N1+ atom.