Dear Ifeffit users: Hello, I have a simple question regarding the 'chi' in the xmu.dat, an output file of FEFF8. I wish I could get helps from you to resolve this. As far as I know... in the xmu.dat file from Feff6, mu=mu0*(1+'chi') as it should be, but in the xmu.dat file from Feff 8, the 'chi' written in the xmu.dat is a rescaled one by mu0/(mu0 at edge+tens eV) so that mu should be equal to mu0+'chi'. I checked up for FEFF8.4 by turning on and off the FMS card, and found that with the FMS card, mu = mu0+'chi', while without the FMS card, mu is quite close to or same as mu0*(1+'chi') instead of mu0+'chi'. Please help me to find which one is correct. Attached are the Feff.inp and the resultant xmu.dat for ZnO. Thank you all. Best Regards, Deok-Yong Cho Post-doctoral researcher at RWTH Aachen, Germany