Hi Abdul, You can, of course, make that assumption but you must realize that by doing so you are imposing a crystallographic constraint which could possibly not be fully reflective of the actual local structure. It all depends on what question you are asking. This is actually a very important point because your assumptions will influence your results. -- Carlo Duchossois Professor of Physics Interim Chair, Chemistry Dept. Sent from mobile device. Please excuse my brevity. On June 14, 2018 7:19:20 AM CDT, ABDUL AHAD wrote:

Thanks for reply,

yes i have to take care of such things. But let me confined us within the limit, suppose the single scattering path is absorber (Cu) to Cu and multi scattering path is absorber to oxygen then back to absorber (forward scattering) and other one is absorber to oxygen then oxygen to Cu and then back to absorber, All of these have same Reff. So my question is can use the same delt_r for all of these path in which only Cu and O take place.

If all of these are different then how?

Thanks in advance