DOE OSTI2020
Re3N4 is Hausmannite-like structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are three inequivalent Re4+ sites. In the first Re4+ site, Re4+ is bonded to six N3- atoms to form ReN6 octahedra that share corners with four equivalent ReN6 octahedra, corners with two equivalent ReN4 tetrahedra, edges with four ReN6 octahedra, and edges with two equivalent ReN4 tetrahedra. The corner-sharing octahedra tilt angles range from 43–45°. There are a spread of Re–N bond distances ranging from 2.12–2.18 Å. In the second Re4+ site, Re4+ is bonded to six N3- atoms to form ReN6 octahedra that share corners with eight ReN6 octahedra, corners with four equivalent ReN4 tetrahedra, edges with two equivalent ReN6 octahedra, and an edgeedge with one ReN4 tetrahedra. The corner-sharing octahedra tilt angles range from 43–45°. There are a spread of Re–N bond distances ranging from 2.07–2.16 Å. In the third Re4+ site, Re4+ is bonded to four N3- atoms to form a mixture of edge and corner-sharing ReN4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–63°. There are a spread of Re–N bond distances ranging from 1.91–1.95 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a rectangular see-saw-like geometry to four Re4+ atoms. In the second N3- site, N3- is bonded in a distorted rectangular see-saw-like geometry to four Re4+ atoms. In the third N3- site, N3- is bonded in a 4-coordinate geometry to four Re4+ atoms.