[Ifeffit] Case of "nonequivalent multiple atomic sites of absorbing atoms"

[Jatinkumar Rana]

Dear Users,

Since long, i was trying to understand the physical meaning of term 
"Delta E0" and "S02" in EXAFS equation. I have little bit of idea about 
both of them. for example, S02 is element specific and it is 
transferable between samples (if we consider same absorbing atom).

However, I am not able to realize their importance in terms of their 
"physical meaning" as far as interaction of photoelectron is concerned. 
Therefore, it is difficult for me to understand their influence on EXAFS.

I am dealing with a case of  "nonequivalent multiple atomic sites of 
absorbing atoms". It is quite obvious that in such kind of case no. of 
variables are more than no. of independent points and there is a need to 
constrain the parameters to solve such problems.

I have following questions :

How do i understand "Delta E0" and "S02" theoretically (in terms of 
photoelectron interaction) ?

Can i constrain "Delta E0" for all absorbing atomic site as same ? (my 
assumption : all absorbing atoms are at same oxidation level)

your comments and suggestions would be highly appreciated...

Best regards,
Rana