[Ifeffit] Rank of path and dopant amp

Hi all I have a question regarding the Rank of path. Since the Rank represent the spectral weight of the particular path. So that if i have a dopant say Ca and it shows the rank 60 while the main atoms shows rank 98. So in order to maintain the doping concentration, what i have to do? for half atomic % doping. do i make the amp of these two as amp*0.5 ? or do i first normalized its by rank and then decide the amp percentage ? Thanks