Dear all,

i have a question about polarization vector in performing the FEFF calculation in Artemis.
I am studying the system CeOBiS2 using Bi L3-edge EXAFS. Starting from *.cif file i'm creating the *.inp file which atoms list come out as follows:

ATOMS                  * this list contains 35 atoms
*   x          y          z     ipot tag           distance
    0.00000    0.00000    0.00000 0 bi            0.00000
    0.00000    0.00000    2.50509 4 s2.1          2.50509
    2.81711    0.00000   -0.12006 4 s1.1          2.81967
   -2.81711    0.00000   -0.12006 4 s1.1          2.81967
    0.00000    2.81711   -0.12006 4 s1.1          2.81967
    0.00000   -2.81711   -0.12006 4 s1.1          2.81967
    0.00000    0.00000   -3.31180 4 s1.2          3.31180
    ...

Bismuth has a S atom sitting on top of him (s2) and it is square coordinated with other four S atoms (s1).
I made measurements on single crystals using fluorescence yield. The experimental geometry consist of the x-ray beam coming at (almost) normal incidence which corresponds to electric field vector lying on the crystal's ab plane.

If I perform the FEFF calculation without taking account of polarization I obtain the first scattering paths which are

1) @S2.1@, Degen = 1, Reff = 2.5051, Rank = 100

2) @S1.1@, Degen = 4, Reff = 2.8197, Rank = 100
3) @S1.2@, Degen = 1, Reff = 3.3118, Rank = 14.78
4) ......

When I insert the line "POLARIZATION 1 0 0" in the imput file i get

1) @S2.1@, Degen = 1, Reff = 2.5051, Rank = 100

2) @S1.1@, Degen = 4, Reff = 2.8197, Rank = 100
3) @S1.2@, Degen = 1, Reff = 3.3118, Rank = 3.67
4) ......

which is exactly the same result for the first 2 scatterings, even if the rank of higher shells is changed...

Now, my question is:

If the components of the polarization vector has to be written in the same reference frame of the atom list i'm expecting to see a strong suppression of the rank factor for the @S2.1@ scattering whose bond is along the z-direction, is it correct?

the .cif file is attached

Thank you in advance,

Eugenio