Have problem with tutorial 3 part 5.

[Ali]

Dear Sir/Madam,

In tutorial 3.5, I don't understand why the following circuit is used for computing band structure:
L (1/2 0 0)
Gamma (0 0 0)
X (0 1/2 1/2)
Gamma (1 1 1)

It is said that the reason is:

"the k-points are specified using reduced coordinates - in agreement with the input setting of the primitive 2-atom unit cell - in standard textbooks, you will often find the L, Gamma or X point given in coordinates of the conventional 8-atom cell : the above-mentioned circuit is then (1/2 1/2 1/2)-(0 0 0)-(1 0 0)-(1 1 1), but such coordinates cannot be used with the 2-atom cell."

But I don't understand it.

Thanks,
Ali