Here are shown the atomic packing schemes for several different crystallographic directions for some hypothetical metal. For each direction the circles represent only those atoms contained within a unit cell, which circles are reduced from their actual size.

(a) To what crystal system does the unit cell belong?
(b) What would this crystal structure be called?

0.40 nm 11001, Io10 0.50 nm 0011 0.64 nm [0111, o1] 0.566 nm [110)