Stefano, Feff6 is an executable. When it runs it needs a file named feff.inp to be in the current working directory, otherwise it will say: Feff 6L.02 Fatal Error: cannot open file "feff.inp" in module rdinp which is exactly what you got when you typed 'feff6' in a directory without a feff.inp file. That doesn't tell us a lot, but it does mean that this version of feff6 is at least not corrupted, so the Installer is probably fine. The first error message from Artemis that you sent: "The error is probably due to having Artemis configured...." and gave an "Uh-Oh" in the Echo Buffer is definitely what Artemis says when it cannot find feff6. You said you got this when the feff_executable was set to 'feff6'. Did you try setting feff_executable to '/Applications/Ifeffit/bin/feff6'? Note that spelling counts. You could open a Terminal, type 'which feff6' and paste that into the feff_executable field. Note to Bruce: How about having a "browse" button for selecting the feff_executable?
I interpret this message with the conclusion that I can just type 'feff6' in the Artemis preferences, as the command is actually seen and of course it is missing the feff.inp file if I run the command from the terminal.
Well, it *should* work that way, but using /Applications/Ifeffit/bin/feff6 will definitely work. It does work for several of us. Hope that helps, --Matt