Friends, Thanks Bruce for forwarding the question to the Ifeffit mailing list regarding background subtraction for samples with strong white lines. The Re sample that sparked the question is attached (white line >3mu). The data is not perfect, but it is good enough for discussion. My first approach to subtracting the background was similar to what Matt mentioned (Matt said: "I know others regularly use kmin >1"), this method seemed to work fairly well using kmin= 1.5 and Rbkg = 1.0. I then used Matt's suggestion to shift the Eo and keep kmin = 0.5, this method ultimately gave a similar subtraction albeit with a phase shift that should be taken care of when the data is fit to theory. It will be interesting to compare the results of the fit using these two methods of background subtraction, especially the first shell which is a Re-CO that has a short distance and is sensitive to background subtraction. Thanks, Dave _________________________________ David Barton, PhD The Dow Chemical Company Catalysis R&D 1776 Building Midland, MI 48674 USA Ph: (989) 636-4753 Fax: (989) 638-6225 Email: dgbarton@dow.com