HI Brandon, If I understand right (and to echo Darius's questions), it seems like you measure samples with a metal reference, and aligned the spectra in Athena so that the references matched. That's a fine way to go. I would ask: how big were the needed energy shifts? Are the experimental mu(E) spectra aligned well at this point? If you're studying metal oxides with different oxygen content, you might very well see oxidation in the XANES. If I understand correctly, you're saying you don't see this. Then, you extracted the chi(k) from the aligned spectra. How much did E0 vary for the shifted spectra in this background-subtraction step? Then, you pulled these chi(k) into Artemis, and see different E0 shifts in the fits. This E0 is a little different, in that it is the E0 shift applied to the Feff calculation to match the experimental spectra. If you use different paths or different calculations, such E0 shifts might happen, and wouldn't be highly meaningful. I know that's not a complete answer, but hopefully that and Darius's questions will help, --Matt PS on Q2: 1/ (kR)^2 vs 1 / kR^2 This is probably either a typo, or a different convention based on the definition of f(k) as the electron scattering amplitude. In the Feff world, it should be 1/kR^2, but using 1/(kR)^2 would just map f(k) to k*f(k).