# [Ifeffit] Commercial MoS2 fit

dmc at pdx.edu dmc at pdx.edu
Thu Nov 11 10:12:34 CST 2004

```Hi List,

I have tried a variety of different things to get this fit to work.  It
seems pretty decent now, although, for my two MS paths (4,5) I had to force the
sO^2's to be positive.  In the process one of them is now zero.  My
parameter 'amp' wants to be 0.5 so I had to set it to 0.7 because I know that
it shouldn't be as low as 1/2.  Changing the k-weight doesn't seem to help.
Here's my Data:

Thanks, Dan

Project title :  Fitting merge 10_15_04.chi
============================================================

Independent points          =      28.581054688
Number of variables         =      13.000000000
Chi-square                  =    5995.284754934
Reduced Chi-square          =     384.780419245
R-factor                    =       0.043668737
Measurement uncertainty (k) =       0.000187262
Measurement uncertainty (R) =       0.006509968
Number of data sets         =       1.000000000

Guess parameters +/- uncertainties  (initial guess):
e0  =    0.8645560   +/-      1.2283680    (guessed as 0.864556 (1.228344))
ss  =    0.0041070   +/-      0.0005190    (guessed as 0.004107 (0.000519))
ss2 =    0.0043590   +/-      0.0005200    (guessed as 0.004359 (0.000520))
ss3 =    0.0217810   +/-      0.0333390    (guessed as 0.021781 (0.033341))
ss4 =    0.0000000   +/-      0.0509500    (guessed as 0.000000 (0.050951))
ss5 =    0.0000360   +/-      0.0063810    (guessed as 0.000036 (0.006382))
ss6 =    0.0028730   +/-      0.0071340    (guessed as 0.002873 (0.007133))
alpha =   -0.0012530   +/-      0.0031940    (guessed as -0.001253 (0.003193))
alpha2 =   0.0075160   +/-      0.0022250    (guessed as 0.007516 (0.002225))
alpha3 =  -0.0171580   +/-      0.0323200    (guessed as -0.017158 (0.032321))
alpha4 =  -0.0165410   +/-      0.1054840    (guessed as -0.016541 (0.105487))
alpha5 =  -0.0181860   +/-      0.0187940    (guessed as -0.018186 (0.018795))
alpha6 =   0.0227330   +/-      0.0147690    (guessed as 0.022733 (0.014767))

Def parameters:
delr_1          =    -0.0057180
delr_2          =     0.0342980
delr_3          =    -0.0782970
delr_4          =    -0.0754820
delr_5          =    -0.0829880
delr_6          =     0.1037370

Set parameters:
amp1            =  .7

Correlations between variables:
ss3 and alpha4     -->  0.8462
e0 and alpha      -->  0.8335
ss4 and alpha3     --> -0.6693
e0 and alpha2     -->  0.6159
ss and ss2        -->  0.6114
alpha5 and alpha6     --> -0.5959
alpha4 and alpha5     --> -0.5821
ss4 and ss5        --> -0.5505
ss3 and alpha5     --> -0.5246
alpha and alpha2     -->  0.5146
ss5 and ss6        --> -0.4931
ss2 and alpha5     -->  0.4681
ss5 and alpha3     -->  0.3885
ss6 and alpha6     -->  0.3700
alpha2 and alpha5     -->  0.3208
ss2 and alpha4     --> -0.2992
ss4 and alpha5     -->  0.2955
ss3 and ss4        -->  0.2923
ss5 and alpha2     --> -0.2842
e0 and alpha4     --> -0.2781
ss2 and ss3        --> -0.2677
alpha3 and alpha5     --> -0.2523
All other correlations are below 0.25

```