Real Space X-ray Absorption Package (RSXAP)

Collection of codes to analyze x-ray absorption data, including EXAFS and XANES

 

The Project

The Real Space X-ray Absorption Package (RSXAP) is a robust collection of codes for analyzing EXAFS and XANES data. These codes do not use some of the common mathematical approximations employed in such analyses. In particular, a background subtraction method is employed that properly normalizes transmission EXAFS data as a function of k, and the pair-distribution function g(r) is directly applied when calculating EXAFS fitting curves. Error analysis utilizes a profiling method that is less dependent on a quadratic surface of the statistical chi^2 as a function of fitting parameters near its minimum. Other functionality includes self-absorption corrections, F-tests (a.k.a. Hamilton tests), and more.

For more information about these codes and their applicability to real-world systems, please consult the following references:

T. M. Hayes and J. B. Boyce, in *Solid State Physics*, ed. by H. Ehrenreich, F. Seitz, and D. Turnbull (Academic, New York, 1982), Vol. 37, p. 173.

G. G. Li, F. Bridges, and C. H. Booth, "XAFS standards: a comparison of experiments and theory." Phys. Rev. B 52, 6332 (1995).

F. Bridges, C. H. Booth, and G. G. Li, "An iterative approach to atomic background removal in XAFS data analysis." Physica B 208&209, 121 (1995).

C. H. Booth and F. Bridges, "Improved self-absorption correction for fluorescence measurements of extended x-ray absorption fine-structure." Physica Scripta, T115, 202-204 (2005).

L. Downward and C. H. Booth and W. W. Lukens and F. Bridges, "A variation of the F-test for determining statistical relevance for particular parameters in EXAFS analysis." In XAFS13: 13th International Conference, July 9-13, 2006, AIP Conf. Proc., 882, 129 (2007). 

C. H. Booth and Y.-J. Hu, "Confirmation of standard error analysis techniques applied to EXAFS using simulations,." In Proceedings of X-Ray Absorption Fine Structure – XAFS14: 14th International Conference, July 26-31, 2009, J. Phys.: Conf. Ser., 190, 012028 (2009).


Basic Documentation

The Code Tree

Note: These codes are difficult to install and use and are not supported to the extent that Demeter and other packages are. Attempt at your own risk!

Stand-alone version of self-absorption correction code

sabcor.tar.gz

Questions?

Contact Corwin Booth at chbooth@lbl.gov if you need further information. I would also appreciate an email if you download this code.