Respected Sir, I am new in the field of EXAFS. I have few questions regarding to IFEFFIT i.e., fitting of theoretical models to the experimental EXAFS data. 1. What is the ideal value of R- factor for any fit. 2. * * Can we use (fit) the theoretical model generated from square pyramidal structure to EXAFS data of octahedral structure by assigning degeneracy of 2 for the apical atom. OR using octalhedral for square planar by not using apical path Yours faithfully Davood Ah. Dar EXAFS research scholar India