Materials Data on TaN2 by Materials Project

Abstract

TaN2 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Ta5+ is bonded to six equivalent N+2.50- atoms to form distorted TaN6 pentagonal pyramids that share corners with six equivalent TaN6 pentagonal pyramids, edges with six equivalent NN8 hexagonal bipyramids, edges with three equivalent TaN6 pentagonal pyramids, and faces with two equivalent TaN6 pentagonal pyramids. All Ta–N bond lengths are 2.11 Å. There are two inequivalent N+2.50- sites. In the first N+2.50- site, N+2.50- is bonded to eight N+2.50- atoms to form NN8 hexagonal bipyramids that share corners with eight equivalent NN8 hexagonal bipyramids and edges with twelve equivalent TaN6 pentagonal pyramids. There are six shorter (2.73 Å) and two longer (2.80 Å) N–N bond lengths. In the second N+2.50- site, N+2.50- is bonded in a square co-planar geometry to four equivalent Ta5+ and two equivalent N+2.50- atoms.