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,
Phone: +61 8 8302 3096
Email: david.weedon@unisa.edu.au