Ok thank u........

Dear sir,

Suppose I have the compound ABC2DE6 (atoms=A, B, C, D, E1, E2 and E3), Orthrombhic structure with space group Amaa, what will be the full occupancy of atoms for the starting model of Rietveld analysis?

I confused about the occupancy of these atoms, please guide me

the occupation number should be a normalized quantity of the site multiplicity, as example the Iron in 2b site should have an occupancy of 0.2 , and the iron in 4f site should have an occupancy of 0.4, and so on, at the beginning of the refinement process, just fix these parameters and let the program refine the profile scale factor, because it has the same effect of increasing the occupancy normalization factor, then you can refine the occupancy which should have a dopent metal

you can check your structure sites from here

http://www.cryst.ehu.es/cryst/get_set.html 

starting model occ. for  compound ABC2DE6 (atoms=A, B, C, D, E1, E2 and E3) are A=1, B=1, C=2,D=1, E1=2, E2=2, E3=2.