Materials Data on Mg2Ta3N5 by Materials Project

Abstract

Mg2Ta3N5 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six N3- atoms to form MgN6 octahedra that share corners with two equivalent MgN6 octahedra, corners with four TaN6 octahedra, edges with three MgN6 octahedra, and edges with nine TaN6 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. There are a spread of Mg–N bond distances ranging from 2.12–2.19 Å. In the second Mg2+ site, Mg2+ is bonded to six N3- atoms to form MgN6 octahedra that share corners with two equivalent TaN6 octahedra, corners with four MgN6 octahedra, edges with three MgN6 octahedra, and edges with nine TaN6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are four shorter (2.18 Å) and two longer (2.19 Å) Mg–N bond lengths. There are three inequivalent Ta+3.67+ sites. In the first Ta+3.67+ site, Ta+3.67+ is bonded to six N3- atoms to form TaN6 octahedra that share corners with two equivalent MgN6 octahedra, corners with four TaN6 octahedra, edges with six MgN6 octahedra, and edges with six TaN6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Ta–N bond distances ranging from 2.16–2.21 Å. In the second Ta+3.67+ site, Ta+3.67+ is bonded to six N3- atoms to form TaN6 octahedra that share corners with six TaN6 octahedra, edges with five TaN6 octahedra, and edges with seven MgN6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Ta–N bond distances ranging from 2.15–2.22 Å. In the third Ta+3.67+ site, Ta+3.67+ is bonded to six N3- atoms to form TaN6 octahedra that share corners with two equivalent TaN6 octahedra, corners with four MgN6 octahedra, edges with five MgN6 octahedra, and edges with seven TaN6 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. There are a spread of Ta–N bond distances ranging from 2.16–2.23 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded to three Mg2+ and three Ta+3.67+ atoms to form NMg3Ta3 octahedra that share corners with six NMg3Ta3 octahedra and edges with twelve NMg2Ta4 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. In the second N3- site, N3- is bonded to two equivalent Mg2+ and four Ta+3.67+ atoms to form a mixture of edge and corner-sharing NMg2Ta4 octahedra. The corner-sharing octahedra tilt angles range from 2–4°. In the third N3- site, N3- is bonded to two equivalent Mg2+ and four Ta+3.67+ atoms to form a mixture of edge and corner-sharing NMg2Ta4 octahedra. The corner-sharing octahedra tilt angles range from 1–2°.