[Ifeffit] Using parameters in Artemis

[David Weedon]

Hi All,

 

I am new to Artemis so these questions are very basic - but
never-the-less confusing to me. I learnt a lot by using Scott Calvin's
ZnO example but ran into trouble when I got to Fit 3. 

 

In the Journal entry we are asked to click "Guess, Def, Set", then click
"new" and enter DelScale = 0.  After I hit the "Guess" button I cannot
find the parameter "dr" on the list.  Am I correct in assuming that "dr"
is some kind of reserved parameter name that should not be used in
equations?  Which leads me to ask several questions (probably silly
questions)???

 

 

QUESTIONS:

 

1                     I presume all the parameters like "amp, deg, delr,
ss2 and enot" relate to the obvious parameters in the EXAFS eqn.
Assigning numerical values makes sense but what is going on when we
create mathematical functions?? Is there a list of functions that we can
model here? Is it somewhere in the software?

 

2                     What are we doing when we make our own parameters?
Are they a mixture of parameters from the EXAFS equation that we wish to
evaluate in the fit, and if so why?

 

3                     The parameter "amp" is defined as the relative
importance of the path and is assigned a value eg. 100 or 30, is this
some form of percentage of this path to the first (major) path?  

 

 

Thanks,

 

Dave

 

 

 

Dr Dave Weedon 

Research Fellow - ACeSSS,

(Applied Centre for Structural and Synchrotron Studies)

Division of Information Technology, Engineering and the Environment,

University of South Australia,

Mawson Lakes, Adelaide,

South Australia, 5095

 

Phone:  +61 8 8302 3096

Email: david.weedon at unisa.edu.au

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20070308/bc787c69/attachment.html>