Show that the structure factor is dependent on the choice of origin whereas the intensity is independent of the choice of origin.

Show that the structure factor is dependent on the choice of origin whereas the intensity is independent of the choice of origin. Consider the case of HCP zinc where two structural description of atomic placements are:
a. Zn atoms at 0 0 0 and 1 3 , 2 3 , 1 2
b. Zn atoms at −1 6 , −1 3 , −1 4 and 1 6 , 1 3 , 1 4