I thought maybe Ken was asking about having box constraints or min/max constraints on parameter values. But that is kind of a guess. Hi Ken, I'm sorry, but I don't quite understand your question. And I have no idea what casaXPS is, so that reference doesn't help me. Are you asking whether you can put gaps in the fit range? B On July 23, 2015, at 8:16 PM, Kenneth Latham wrote: Hi Bruce, Is it possible to set a range of values that the the center (or any other values) can be between for line shapes when peak fitting in Athena? Similar to what you can do in CasaXPS. If not, do you know of a program that can handle NEXAFS peak fitting and has that feature? Cheers, Ken _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit