Hi Matt
As I am new to FEFF, I was estimating SO2 to be equal to 1 for XANES. But I don't know if it was good to have such guess or not.
OK. Just be be clear, using S02=0 will tell Feff to *not* set S02 to 1, and that will alter the result.
By changing Exchange card from 0 0 0 0 to 0 0 0 2, I am getting a noticeable change in absorption edge.
OK, that's good. Using a ground state potential should give different results from using the Hedin-Lundquist model.
Were you expecting to change this parameter and get no change in output?
The edge showed a little shift to higher energy and also slight fall in amplitude of edge. These changes are not ignorable. So I am confused about what approach to follow.
There are a number of parameters for Feff9, and changing these does typically alter the result -- it's more or less why they exist.
Sorry if this sounds curt of impolite, but I don't understand what you are expecting to happen.
What are you hoping to get out of these calculations?