The accompanying diagram below shows the atomic packing schemes for several crystallographic directions in a hypothetical compound between two elements. The circles represent only the atoms contained within a unit cell for each direction. The circles are reduced from their actual size. The atoms are equally spaced along each direction. The different colours of the atoms refer to each of the two elements in the compound. (Since parallel directions have the same indices, there are sometimes different possibilities for the atoms depending on where you start in the unit cell.)
0.806nm
[001]:
0.230nm
[100], [010], [110]:
0.460nm
[201], [021]:
0.636nm
[2-2 1]
(a) To what crystal system does the unit cell belong?
(b) Sketch and label a cell of the compound.
(c) Determine the type of structure of the unit cell (eg. Body Cantered Cubic, Face Cantered Cubic, etc)