Dear All: I would like to attempt fits to the pre-edge features of a set of Fe K-edge XANES spectra for Fe(II) samples that show partial oxidation with the goal of determining whether Fe(III) exists in octahedral or tetrahedral coordination (e.g. Wilke et al., American Mineralogist, 2001). Broadly, the fitting procedure involves extracting the pre-edge feature from the edge using a spline function and then deconvoluting this feature using a set of pseudo-voigt functions. I believe that I can use the LCF module in Sixpack to fit the feature using the pseudo-voigt functions, but I'm having trouble extracting the pre-edge feature. I've tried using the spline function in Sixpack (and Athena), but I don't have enough options to modify the spline. It seems to me that I need to use a very rigid spline (for instance, one with only 3 or so knots), and that the options in Sixpack and Athena don't allow for this. I heard the program exafspak would allow me more freedom to control the spline function, but I haven't been able to successfully download the program, let alone use it. So, my questions are the following: (1) Is there a program other than exafspak that I could use to fit a spline to my data where I would have more control over the spline options? I would prefer not to use exafspak since my knowledge of unix is nil. (2) Has anyone used exafspak on a mac? I'm using OS 10.5.8 and I'd appreciate any tips you might be able to give me on installing the program. I followed the directions for installation provided on the website, but the command to install the program (i.e. "add_exafs") wasn't recognized. Thanks for your help! Sharon