Artemis: How to treat Neglected? DS path
Dear all, I have been analyzing some EXAFS data based on crystal structure by Artemis. The model construction and analysis within the First shell had come along OK. And I would like to refine the analysis of higher shell including multiple scattering. But the problem about "How to treat the MS path(especially DS)" is existing in the way to goal. Generally, Considering triangle arrangement (A-B-C; A is Absorber, B is nearest neighbor, C is the next neighbor) offers the possibility of two double scattering paths. Stated another way, the following two type can be readily considerable. "Type I: A-->B-->C-->A and Type II; A-->C-->B-->A" By calculation of FEFF on Artemis, a number of DS is computed and listed, of course on my computer. However, I could find JUST ONLY type II double scatter, no type I. In this case, should I simply multiply the amplitude by two? Or, are there reasonable answer to neglected type I path? I will be glad with your help. Best regards, Takahide
Have you checked the value of the degeneracy of this path? IMHO A-B-C-A and A-C-B-A paths are identical best regards Dariusz W dniu 12-02-03 09:31, Takahide Yamaguchi pisze:
Dear all,
I have been analyzing some EXAFS data based on crystal structure by Artemis.
The model construction and analysis within the First shell had come along OK. And I would like to refine the analysis of higher shell including multiple scattering.
But the problem about "How to treat the MS path(especially DS)" is existing in the way to goal.
Generally, Considering triangle arrangement (A-B-C; A is Absorber, B is nearest neighbor, C is the next neighbor) offers the possibility of two double scattering paths. Stated another way, the following two type can be readily considerable.
"Type I: A-->B-->C-->A and Type II; A-->C-->B-->A"
By calculation of FEFF on Artemis, a number of DS is computed and listed, of course on my computer. However, I could find JUST ONLY type II double scatter, no type I.
In this case, should I simply multiply the amplitude by two?
Or, are there reasonable answer to neglected type I path?
I will be glad with your help.
Best regards, Takahide
_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
Hi Takahide, See the first full paragraph below equation A.1 in Zabinski et al, Phys. Rev. B 52, 2995–3009 (1995), http://dx.doi.org/10.1103/PhysRevB.52.2995 Regards, B ________________________________________ From: ifeffit-bounces@millenia.cars.aps.anl.gov [ifeffit-bounces@millenia.cars.aps.anl.gov] on behalf of Takahide Yamaguchi [11nm023s@mcs.ibaraki.ac.jp] Sent: Friday, February 03, 2012 3:31 AM To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] Artemis: How to treat Neglected? DS path Dear all, I have been analyzing some EXAFS data based on crystal structure by Artemis. The model construction and analysis within the First shell had come along OK. And I would like to refine the analysis of higher shell including multiple scattering. But the problem about "How to treat the MS path(especially DS)" is existing in the way to goal. Generally, Considering triangle arrangement (A-B-C; A is Absorber, B is nearest neighbor, C is the next neighbor) offers the possibility of two double scattering paths. Stated another way, the following two type can be readily considerable. "Type I: A-->B-->C-->A and Type II; A-->C-->B-->A" By calculation of FEFF on Artemis, a number of DS is computed and listed, of course on my computer. However, I could find JUST ONLY type II double scatter, no type I. In this case, should I simply multiply the amplitude by two? Or, are there reasonable answer to neglected type I path? I will be glad with your help. Best regards, Takahide _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
participants (3)
-
"Dr. Dariusz A. Zając" -
Ravel, Bruce -
Takahide Yamaguchi