Materials Data on Ca2TaN3 by Materials Project

Abstract

Ca2TaN3 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven N3- atoms. There are a spread of Ca–N bond distances ranging from 2.36–3.09 Å. In the second Ca2+ site, Ca2+ is bonded to seven N3- atoms to form distorted CaN7 pentagonal bipyramids that share corners with four equivalent CaN7 pentagonal bipyramids, a cornercorner with one TaN4 tetrahedra, edges with three equivalent CaN7 pentagonal bipyramids, and edges with four equivalent TaN4 tetrahedra. There are a spread of Ca–N bond distances ranging from 2.40–3.03 Å. Ta5+ is bonded to four N3- atoms to form TaN4 tetrahedra that share a cornercorner with one CaN7 pentagonal bipyramid, corners with two equivalent TaN4 tetrahedra, and edges with four equivalent CaN7 pentagonal bipyramids. There are a spread of Ta–N bond distances ranging from 1.91–1.97 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a 4-coordinate geometry to four Ca2+ and two equivalent Ta5+ atoms. In the second N3- site, N3- is bonded in a 6-coordinate geometry to five Ca2+ and one Ta5+ atom. In the third N3- site, N3- is bonded to five Ca2+ and one Ta5+ atom to form a mixture of distorted edge and corner-sharing NCa5Ta octahedra. The corner-sharing octahedral tilt angles are 18°.