Dear All, I need some help in fitting an amorphous iron oxyhydoxide sample. I am having difficulty producing a good fit, particularly in the k=4-6 range. Fitting this region well is very important for me, because if I add another metal(+3 oxidation state) into my system, this is where I observe the most quantifiable changes (The shoulder @ 5 A^-1 and the min @ 5.6 A^-1). Thus far I have been unable to fit the shoulder well enough to make meaningful comparisons. I have been fitting in kq with kmin=2.566 And kmax=10.877, and Rmin=1 and Rmax=3.5, and using the goethite O1.1, Fe.1, and Fe.3 paths. Attached is an Artemis file (P41_006_merge_norm_TRANS.fpj) for an amorphous Fe oxyhydroxide sample (Fe only, no other metals). The data was collected at the Fe K-edge. *Is there a way to fit just this region (k~4-6 range) in k? If so what is the best method for doing this? If not, does anyone have suggestions as to how I can improve my fitting? Should I fit the data in k since the shoulder is less evident in kq?* Thank you for your time. Sincerely, Matt Frith