Materials Data on Ta3Cr5N4 by Materials Project

Abstract

(CrTaN)2TaCr3N2 crystallizes in the tetragonal P4mm space group. The structure is two-dimensional and consists of one CrTaN sheet oriented in the (0, 0, 1) direction and one TaCr3N2 sheet oriented in the (0, 0, 1) direction. In the CrTaN sheet, there are two inequivalent Ta sites. In the first Ta site, Ta is bonded to five N atoms to form a mixture of distorted corner and edge-sharing TaN5 square pyramids. There are four shorter (2.14 Å) and one longer (2.30 Å) Ta–N bond lengths. In the second Ta site, Ta is bonded to five N atoms to form a mixture of distorted corner and edge-sharing TaN5 square pyramids. There are four shorter (2.14 Å) and one longer (2.32 Å) Ta–N bond lengths. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a single-bond geometry to one N atom. The Cr–N bond length is 2.10 Å. In the second Cr site, Cr is bonded in a single-bond geometry to one N atom. The Cr–N bond length is 2.08 Å. There are two inequivalent N sites. In the first N site, N is bonded to five Ta and one Cr atom to form a mixture of corner and edge-sharing NTa5Cr octahedra. The corner-sharing octahedral tilt angles are 19°. In the second N site, N is bonded to five Ta and one Cr atom to form a mixture of corner and edge-sharing NTa5Cr octahedra. The corner-sharing octahedral tilt angles are 18°. In the TaCr3N2 sheet, Ta is bonded to five N atoms to form TaN5 square pyramids that share corners with four equivalent TaN5 square pyramids, edges with four equivalent TaN5 square pyramids, and edges with four equivalent CrN5 square pyramids. There are four shorter (2.13 Å) and one longer (2.23 Å) Ta–N bond lengths. There are three inequivalent Cr sites. In the first Cr site, Cr is bonded in a single-bond geometry to one N atom. The Cr–N bond length is 2.06 Å. In the second Cr site, Cr is bonded in a single-bond geometry to one N atom. The Cr–N bond length is 1.87 Å. In the third Cr site, Cr is bonded to five N atoms to form CrN5 square pyramids that share corners with four equivalent CrN5 square pyramids, edges with four equivalent TaN5 square pyramids, and edges with four equivalent CrN5 square pyramids. There are four shorter (2.12 Å) and one longer (2.17 Å) Cr–N bond lengths. There are two inequivalent N sites. In the first N site, N is bonded to four equivalent Ta and two Cr atoms to form a mixture of corner and edge-sharing NTa4Cr2 octahedra. The corner-sharing octahedral tilt angles are 15°. In the second N site, N is bonded to one Ta and five Cr atoms to form NTaCr5 octahedra that share corners with four equivalent NTaCr5 octahedra and edges with eight NTa4Cr2 octahedra. The corner-sharing octahedral tilt angles are 12°.