Materials Data on HfNCl by Materials Project
HfNCl crystallizes in the trigonal R-3m space group. The structure is two-dimensional and consists of three HfNCl sheets oriented in the (0, 0, 1) direction. Hf4+ is bonded in a 7-coordinate geometry to four equivalent N3- and three equivalent Cl1- atoms. There are three shorter (2.11 Å) and one longer (2.18 Å) Hf–N bond lengths. All Hf–Cl bond lengths are 2.75 Å. N3- is bonded to four equivalent Hf4+ atoms to form a mixture of edge and corner-sharing NHf4 tetrahedra. Cl1- is bonded in a 3-coordinate geometry to three equivalent Hf4+ atoms.