Hello, everyone, I am doing the time-resolved XAFS, pump-pulse technique. Sample is Cu2Ti2O5, the absorber is Cu, the scatter is Ti. With photoexcitation, the one electron is excited from Cu site and transfer to neighbor Ti site. My question is how to model this photoexcited charge transfer on the FEFF software? I have tried as below: First method, To separate the absorber Cu and neighbor scattering Ti with other Cu and Ti ions, I create a cluster and modify the POTENTIALS and ION card: POTENTIALS 0 29 Cu (absorber, charge +1) 1 29 Cu 2 22 Ti 3 8 O 4 22 Ti (neighbor scatter, charge -1) ION 0 -1 ION 4 1 The results shows the chi.dat file is same for with or without ION card. Second method, Use the same cluster as the first method and the use the CONFIG card to model the charge transfer: CONFIG card 2 0 Cu Ar 3d 4 6 4s 0 4p 0 #(lost on electron from 4s) 4 Ti Ar 3d 2 0 4s 2 4p 1 #(receive on electron to 4p) But this method gives error before the run. Can some body tell where I am wrong? Best regards, Fan