DESCRIPTION
This provides class methods for computing corrections to fluorescence EXAFS data due to normalization, I0, and selfabsorption effects. The corrections are computed from xray absorption coefficients provided by the Xray::Absorption package.METHODS
Note that the values returned for all methods depend on the data resource used. See Xray::Absorption. "mcmaster"

This is called "mcmaster" for historical reasons. It calculates the
normalization correcion for a given element.
$sigma_mm = Xray::FluorescenceEXAFS>mcmaster($element, $edge);
It takes the central atoms tag and the alphanumeric edge symbol as arguments and returns the normalization correction in units of Angstrom squared.
"normalization" and "edgestep" are aliases for this method.
 "i0"

This calculates the correcion due to the I0 fill gases in a
fluorescence experiment.
$gases = {nitrogen=>$nitrogen, argon=>$argon, krypton=>$krypton}; $sigma_i0 = Xray::FluorescenceEXAFS>i_zero($central, $edge, $gases);
It takes the central atoms tag, the alphanumeric edge symbol, and a reference to a hash containing the volume percentages of the three gases as arguments. It assumes that any remaining volume is filled with helium and it correctly accounts for the fact that nitrogen is a diatom. It returns the I0 correction in units of Angstrom squared.
"i_zero" and "izero" are aliases for this method.
 "self"

This calculates the correcion due to selfabsorption fluorescence
experiment. It assumes that the sample is infinately thick and that
the entry and exit angles of the photons are the same.
$contents = {Y=>1, Ba=>2, Cu=>3, O=>7}; ($amp_i0, $sigma_i0) = Xray::FluorescenceEXAFS>self($central, $edge, $contents);
It takes the central atoms tag, the alphanumeric edge symbol, and a reference to a hash which counts the atoms in the unit cell. It returns a list whose zeroth element is the multiplicative amplitude correction and whose first element is the sigma^2 correction in units of Angstrom squared.
"overabsorption" is an aliases for this method.
BUGS AND LIMITATIONS
 Fourth cumulant corrections are not calculated.
 Geometry and thickness effects are not included in the self absorption calculation
Please report problems to Bruce Ravel (bravel AT bnl DOT gov)
Patches are welcome.
AUTHOR
Bruce Ravel (bravel AT bnl DOT gov)LICENCE AND COPYRIGHT
Copyright (c) 20062008 Bruce Ravel (bravel AT bnl DOT gov). All rights reserved.This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.