Materials Data on HfNF4 by Materials Project
(HfF4)2N2 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of four ammonia molecules and one HfF4 sheet oriented in the (0, 0, 1) direction. In the HfF4 sheet, there are two inequivalent Hf sites. In the first Hf site, Hf is bonded in a 7-coordinate geometry to seven F atoms. There are a spread of Hf–F bond distances ranging from 1.89–2.22 Å. In the second Hf site, Hf is bonded to seven F atoms to form distorted edge-sharing HfF7 pentagonal bipyramids. There are a spread of Hf–F bond distances ranging from 1.89–2.15 Å. There are eight inequivalent F sites. In the first F site, F is bonded in a bent 150 degrees geometry to two Hf atoms. In the second F site, F is bonded in a linear geometry to two Hf atoms. In the third F site, F is bonded in a bent 150 degrees geometry to two Hf atoms. In the fourth F site, F is bonded in a bent 120 degrees geometry to two Hf atoms. In the fifth F site, F is bonded in a water-like geometry to two equivalent Hf atoms. In the sixth F site, F is bonded in a water-like geometry to two equivalent Hf atoms. In the seventh F site, F is bonded in a single-bond geometry to one Hf atom. In the eighth F site, F is bonded in a single-bond geometry to one Hf atom.