[Ifeffit] FEFF simulation of DFT optimized structure at Fe K-edge

Dear all, Thank you very much for answering many questions related to XAS! I am working on Fe modified zeolites and trying to simulate the Fe K-edge XANES using DFT optimized structures by FEFF10. I found the shape of simulated results are quite similar to the experimental data. However, there is an around 1.4 eV difference between the edge positions of the experimental data and the simulated results. I have calibrated the experimental spectra using reference sample (Fe foil) measured at the same time at synchrotron. I wonder if there are some methods to calibrate the edge energy of the simulated results. Thanks a lot for your help! Best regards, Harry