Materials Data on AlNF4 by Materials Project

Abstract

(Al5(NF5)4)2N2 crystallizes in the tetragonal I4/mcm space group. The structure is two-dimensional and consists of four ammonia molecules and two Al5(NF5)4 sheets oriented in the (0, 0, 1) direction. In each Al5(NF5)4 sheet, there are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles are 30°. There is two shorter (1.74 Å) and four longer (1.85 Å) Al–F bond length. In the second Al3+ site, Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedra tilt angles range from 3–37°. There are a spread of Al–F bond distances ranging from 1.76–1.88 Å. N1+ is bonded in a bent 150 degrees geometry to two equivalent F1- atoms. Both N–F bond lengths are 1.74 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a water-like geometry to one Al3+ and one N1+ atom. In the second F1- site, F1- is bonded in a bent 150 degrees geometry to two Al3+ atoms. In the third F1- site, F1- is bonded in a single-bond geometry to one Al3+ atom. In the fourth F1- site, F1- is bonded in a linear geometry to two equivalent Al3+ atoms. In the fifth F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent Al3+ atoms.