B31Si11
Magnusson, B.Brosset, C.
Acta Chemica Scandinavica (1-27,1973-42,1988) (1962) 16, 449-455
a=6.319Å b=6.319Å c=12.713Å
α=90° β=90° γ=120°
B4Si
Brosset, C.Magnusson, B.
Nature (London) (1960) 187, 54-55