feffit_1.inp

%       Copyright (c) 2000 Bruce Ravel
%       Permission is granted to copy, distribute and/or modify this
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%       Foundation; with the Invariant Sections being "EXAFS Analysis
%       Using FEFF and FEFFIT, Part 1: Presentation", "EXAFS Analysis
%       Using FEFF and FEFFIT, Part 2: Commentary", and all related
%       analysis examples, with no Front-Cover Texts, and with no
%       Back-Cover Texts.  A copy of the license is included in the
%       section entitled "GNU Free Documentation License".
% 
% 
% This file (and all files associated with `EXAFS Analysis Using FEFF
% and FEFFIT') are free documentation; you can redistribute it and/or
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title =  Copper example, first shell
data = data/cu10kk.chi
out = fits/cu10k
kmin = 2	kmax = 18	dk = 1	kw = 1
rmin = 1	rmax = 3

format = ascii  all = no
rspout = yes	qspout = no	kspout = yes

%% -------------------------------------------------------------------
%% Do you want to just do a Fourier transform of the data?  Uncomment
%% the following line:
%        end
%% Everything after the "end" keyword is ignored by feffit.
%% -------------------------------------------------------------------



%% The following is a simple single-shell fit.  This is the simplest
%% possible use of feffit.   In this way, feffit is being used much
%% like any single-shell, single-scattering, Fourier-filtering fitting
%% program.  While this is not a very sophisticated use of feffit, it
%% does demonstrate feffit's syntax.

%% The first thing to do is the define some variables.  This may seem
%% like an unnecessary level of abstraction at this stage, but you
%% will see in later examples how very useful this is.

%% We define four parameters -- enough to fit the first shell of the
%% copper data -- S0^2, and e0 shift, a deltaR for the path, and a
%% Debye-Waller factor.  This is done with the guess keyword.

%==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==
guess	amp	0.9
guess	e0	0.0
guess	sig	0.003
guess	deltaR	0.0
%==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==


%% Now we tell feffit to read the feffNNNN.dat file from the feff
%% calculation which contains the first-shell SS contribution.  We
%% then use the variables defined above as the terms in the exafs
%% equation for the first shell.

path	1	feff/feff0001.dat
id	1	First shell SS, deg=12.000, r_eff=2.5527
delr	1	deltaR
sigma2	1	sig
s02	1	amp
e0	1	e0

%% Note that the guess parameter used for delr need not be called
%% deltaR.  It could be called "fred" as in
%%   guess   fred   0.0
%%   delr    1      fred
%% The same goes for the sigma^2 parameter.  Again, this layer of
%% abstraction may seem unnecessary, but later examples will prove its
%% usefulness.

%% Run this fit and look at the output by overplotting the files
%% fits/cu10kr.dat and fits/cu10kr.fit.



!!&& Local Variables:
!!&& input-k-weight: "1"
!!&& input-out-path: "fits/"
!!&& input-feff-path: "feff/"
!!&& input-data-path: "data/"
!!&& input-program-name: "feffit"
!!&& End:
%# Input-mode Time-stamp: <2000/06/11 10:03:47 bruce>