[Ifeffit] Fitting Commercial Molybdenum Disulfide

dmc at pdx.edu dmc at pdx.edu
Fri Oct 29 12:24:38 CDT 2004

```Dear List,

Thanks for all the good suggestions.  Here's how my fit stands at this
point.  I have a few multiple scattering paths at 3.989, in order to excude
these 2 I put the R-range from 1-3.975.  It seems that you think I should
include these paths, if so, do I treat them a little differently.  They don't
seem to help the fit using the same parameter strategy.  Additionally, I
extended the k-range from 2-13.5 to 2-15.  This seemed to improve the reduced
chi-square dramatically.

Thanks Again, Dan

One Eo, seperate ss's, seperate Delr's, expanded k, R ranges:

Independent points          =      24.281250000
Number of variables         =       7.000000000
Chi-square                  =    6436.437226455
Reduced Chi-square          =     372.452063737
R-factor                    =       0.047313433
Measurement uncertainty (k) =       0.000187262
Measurement uncertainty (R) =       0.006509968
Number of data sets         =       1.000000000

Guess parameters +/- uncertainties  (initial guess):
ss              =     0.0041180   +/-      0.0005120    (guessed as 0.004636
(0.000411))
e0              =     0.8351420   +/-      1.1214120    (guessed as 1.765958
(1.154388))
alpha           =    -0.0012160   +/-      0.0030000    (guessed as 0.001090
(0.002843))
ss2             =     0.0044650   +/-      0.0004590    (0.0000)
ss3             =     0.0284980   +/-      0.0234700    (0.0000)
alpha2          =     0.0070700   +/-      0.0020190    (0.0000)
alpha3          =    -0.0267670   +/-      0.0318320    (0.0000)

Def parameters:
delr_1          =    -0.0048260
delr_2          =     0.0280560
delr_3          =    -0.1062180

Set parameters:
amp             =  0.7

Correlations between variables:
e0 and alpha      -->  0.8148
e0 and alpha2     -->  0.6596
alpha and alpha2     -->  0.5393
ss3 and alpha3     -->  0.3825
e0 and alpha3     --> -0.2940
All other correlations are below 0.25

```