Dear All,

I met a problem in fitting my sample. The sample is a very simple crystalline Ni (fcc) with minor Pd. I measured both the K-edge of Ni and Pd and fit with a 55 randomly distributed cluster model (from calculations). The model suggested that there are 1 Pd in the first and second-shell, 6-Pd in the 3rd-shell and 2-Pd in the 4th shell. I have attached the FPJ file here, can anyone help me to have a look.

1. In fitting the K-edge of Pd, most paths are single scattering, but I always get a shorter Pd-Pd length than Pd-Ni, even I tried to include all the paths. Not sure if I made any mistakes in the path parameters settings. 

2. If including the minor contribution paths, I use the same parameters for the path: @Ni1.1 Ni1.1@ (acute triangle) and the path: @N1.1 Ni1.1@ (obtuse triangle), as well as single scattering path @Ni1.1@. I know there's a problem (though no much effect on the results), but don't know how to set the first two paths' parameters

3. If the result is correct, which may suggest there is no Pd in the 1st-shell, but how to fit the coordination number of Pd is a problem. Since Pd is only 1/12 in the first shell, while the uncertainty of CN from EXAFS fitting is pretty large. Does it make a sense to refine the CN?

FPJ file is attached

Thank you very much

Fuxiang Zhang