software to fit optical spectra - Quantum Materials Group

It is tempting to press immediately the button, but this wouldn’t work until we tell
the program that we want to fit the “R1.DAT” dataset to the model “Model1”. The way to do it
is to add the corresponding term to the chi-square (Equation 2-12). Click the button.The
window “Add ChiSq term” will show up (Figure 3-13). In the list “Available ChiSq terms”
there is only one possibility: “[R] “R1.DAT”-“Model1”” (there would be much more if more
models and datasets were available). Select this item and click .
Figure 3-13 Adding chi-square terms.
Now the fitting problem is well specified (Figure 3-14). The number of points in the
spectrum is 4792 and the number of fitted parameters is 7. You can also see how big the chisquare
is.
Figure 3-14 The “Fit” window after the adding of a chi-square term.
Now we can press the button. You might notice that the match considerably
improved (Figure 3-15) and the chi-square has decreased more than 10 times. It is a good idea
save the model again, perhaps with a different name, e.g., “MODEL2.RFM”.
Guide to RefFIT Page 32