F15Nb6
Schaefer, H.von Schnering, H.G.Niehues, K.J.Nieder Vahrenholz, H.G.
Journal of the Less-Common Metals (1965) 9, 95-104
a=8.19Å b=8.19Å c=8.19Å
α=90° β=90° γ=90°