Materials Data on CrN2 by Materials Project

Abstract

CrN2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Cr6+ sites. In the first Cr6+ site, Cr6+ is bonded to five N3- atoms to form CrN5 trigonal bipyramids that share corners with three CrN4 tetrahedra, corners with two equivalent CrN5 trigonal bipyramids, and an edgeedge with one CrN5 trigonal bipyramid. There are a spread of Cr–N bond distances ranging from 1.66–1.97 Å. In the second Cr6+ site, Cr6+ is bonded to four N3- atoms to form CrN4 tetrahedra that share corners with two equivalent CrN4 tetrahedra and corners with three CrN5 trigonal bipyramids. There are a spread of Cr–N bond distances ranging from 1.64–1.89 Å. In the third Cr6+ site, Cr6+ is bonded to five N3- atoms to form distorted CrN5 trigonal bipyramids that share corners with three CrN4 tetrahedra, corners with two equivalent CrN5 trigonal bipyramids, and an edgeedge with one CrN5 trigonal bipyramid. There are a spread of Cr–N bond distances ranging from 1.62–2.08 Å. In the fourth Cr6+ site, Cr6+ is bonded to four N3- atoms to form CrN4 tetrahedra that share corners with two equivalent CrN4 tetrahedra and corners with three CrN5 trigonal bipyramids. There are a spread of Cr–N bond distances ranging from 1.66–1.84 Å. There are eight inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to three Cr6+ atoms. In the second N3- site, N3- is bonded in a bent 150 degrees geometry to two Cr6+ atoms. In the third N3- site, N3- is bonded in a bent 150 degrees geometry to two Cr6+ atoms. In the fourth N3- site, N3- is bonded in a distorted linear geometry to two Cr6+ atoms. In the fifth N3- site, N3- is bonded in a bent 150 degrees geometry to two Cr6+ atoms. In the sixth N3- site, N3- is bonded in a distorted T-shaped geometry to three Cr6+ atoms. In the seventh N3- site, N3- is bonded in a bent 120 degrees geometry to two Cr6+ atoms. In the eighth N3- site, N3- is bonded in a linear geometry to two Cr6+ atoms.