Materials Data on NbCrN2 by Materials Project

Abstract

CrNbN2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Nb3+ is bonded to five equivalent N3- atoms to form a mixture of edge and corner-sharing NbN5 square pyramids. There are one shorter (2.21 Å) and four longer (2.27 Å) Nb–N bond lengths. Cr3+ is bonded in a 5-coordinate geometry to five N3- atoms. There is four shorter (1.91 Å) and one longer (1.92 Å) Cr–N bond length. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to five equivalent Nb3+ and one Cr3+ atom to form NNb5Cr octahedra that share corners with four equivalent NNb5Cr octahedra, corners with four equivalent NCr4 tetrahedra, and edges with eight equivalent NNb5Cr octahedra. The corner-sharing octahedral tilt angles are 12°. In the second N3- site, N3- is bonded to four equivalent Cr3+ atoms to form NCr4 tetrahedra that share corners with four equivalent NNb5Cr octahedra, corners with four equivalent NCr4 tetrahedra, and edges with four equivalent NCr4 tetrahedra. The corner-sharing octahedral tilt angles are 57°.