Hf3N4
Zerr, A.Miehe, G.Riedel, R.
Nature Materials (2003) 2, 3 185-189
a=6.701Å b=6.701Å c=6.701Å
α=90° β=90° γ=90°
N4Zr3
a=6.74Å b=6.74Å c=6.74Å