Hi I would like to know what is the exact way to find the edge position of a sample, and I wonder If anyone can help. Currently, I analyze few samples with minor changes, and I suspect those changes might affect edge shifts. The different samples are absolutely aligned, and the next step is to find the edge position of each, and compare the shifts with respect to the reference. When using ATHENA, a circle appears approximately where the edge should be, whereas a different result for the edge position appears when analyzing with UWEXAFS package � by viewing the maximum point of the first derivative of mu(E). I would also like to know, what is the correct definition of the edge position. Thanks. Gabi. __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free web site building tool. Try it! http://webhosting.yahoo.com/ps/sb/