[Ifeffit] Fitting Commercial Molybdenum Disulfide
dmc at pdx.edu
dmc at pdx.edu
Thu Nov 4 11:18:34 CST 2004
Hi List,
Here's my most recent data. I was able to look at the individual paths
and changed my R-range to 2-4.5 angstroms on the first set of data, I set the
second set of data to the same range, although 4 works better as a maximum for
that set. The k-range on the second range had to be truncated though.
Six paths are used for each fit, same parameters, except for amp (0.7 for one
~0.8 for the other). The seperate data sets still have a few parameters that
are outside of the error bars of the other (ss2,ss3,ss4,alpha, alpha2,alpha5).
What can I do to get these beamlines to agree?
delr_# define alpha# * reff
all other parameters guessed.
ss for each path, only one e0 for all
Thanks for the help, Dan
First Data set -- Full k-range works best, Full range used for fit.
Project title : Fitting merge 10_15_04.chi
Guess parameters +/- uncertainties (initial guess):
e0 = 0.8686930 +/- 1.1038290 (guessed as 0.868694 (1.103841))
ss = 0.0041150 +/- 0.0004990 (guessed as 0.004115 (0.000499))
ss2 = 0.0044360 +/- 0.0004450 (guessed as 0.004436 (0.000445))
ss3 = 0.0243560 +/- 0.0201400 (guessed as 0.024368 (0.020159))
ss4 = -0.0065470 +/- 0.0047820 (guessed as -0.006545 (0.004786))
ss5 = -0.0016100 +/- 0.0050490 (guessed as -0.001611 (0.005047))
ss6 = 0.0059980 +/- 0.0139390 (guessed as 0.005996 (0.013935))
alpha = -0.0011360 +/- 0.0029380 (guessed as -0.001136 (0.002938))
alpha2 = 0.0071480 +/- 0.0019780 (guessed as 0.007148 (0.001978))
alpha3 = -0.0060900 +/- 0.0273580 (guessed as -0.006078 (0.027378))
alpha4 = -0.0198570 +/- 0.0154200 (guessed as -0.019851 (0.015430))
alpha5 = 0.1399050 +/- 0.0148530 (guessed as 0.139906 (0.014848))
alpha6 = 0.0199630 +/- 0.0268690 (guessed as 0.019961 (0.026862))
Def parameters:
delr_1 = -0.0051820
delr_2 = 0.0326180
delr_3 = -0.0277930
delr_4 = -0.0906110
delr_5 = 0.6384270
delr_6 = 0.0910950
Set parameters:
amp1 = .7
Correlations between variables:
e0 and alpha --> 0.8170
e0 and alpha2 --> 0.6726
ss and ss2 --> 0.6591
alpha and alpha2 --> 0.5516
alpha5 and alpha6 --> -0.4856
e0 and alpha3 --> 0.4083
alpha3 and alpha4 --> 0.3588
ss5 and ss6 --> -0.3581
alpha and alpha3 --> 0.3100
alpha2 and alpha3 --> 0.3045
ss2 and alpha6 --> 0.2745
e0 and ss3 --> 0.2649
ss and ss3 --> 0.2627
ss2 and ss3 --> 0.2626
ss6 and alpha5 --> -0.2510
All other correlations are below 0.25
Second Data Set -- Trucated k-range (2-13.5)
Project title : Fitting merge 10_15_04.chi
Independent points = 25.270507813
Number of variables = 14.000000000
Chi-square = 1202.598221935
Reduced Chi-square = 106.703108852
R-factor = 0.057229121
Measurement uncertainty (k) = 0.000827712
Measurement uncertainty (R) = 0.022111003
Number of data sets = 1.000000000
Guess parameters +/- uncertainties (initial guess):
amp = 0.7976070 +/- 0.1361170 (guessed as 0.776348 (0.139898))
ss = 0.0037770 +/- 0.0015530 (guessed as 0.003589 (0.001617))
e0 = 0.5608430 +/- 1.8018380 (guessed as 0.642687 (1.861307))
alpha = -0.0061290 +/- 0.0049080 (guessed as -0.005966 (0.005078))
ss2 = 0.0029050 +/- 0.0009970 (guessed as 0.002686 (0.001078))
ss3 = 0.0075410 +/- 0.0094220 (guessed as 0.005992 (0.008858))
ss4 = -0.0110250 +/- 0.0035850 (guessed as -0.011776 (0.004653))
ss5 = -0.0042000 +/- 0.0078070 (guessed as -0.007610 (0.005250))
alpha2 = 0.0038110 +/- 0.0030450 (guessed as 0.003762 (0.003187))
alpha3 = -0.0037820 +/- 0.0145580 (guessed as 0.001200 (0.015976))
alpha4 = -0.0212550 +/- 0.0107080 (guessed as -0.011852 (0.014417))
alpha5 = 0.1151980 +/- 0.0236640 (guessed as 0.113430 (0.014973))
ss6 = 0.0028560 +/- 0.0166050 (guessed as -0.007250 (0.003624))
alpha6 = 0.0193530 +/- 0.0299640 (guessed as 0.001791 (0.008195))
Def parameters:
delr_1 = -0.0279670
delr_2 = 0.0173920
delr_3 = -0.0172570
delr_4 = -0.0969910
delr_5 = 0.5256830
delr_6 = 0.0883130
Correlations between variables:
amp and ss --> 0.8382
e0 and alpha --> 0.8048
amp and ss2 --> 0.7964
e0 and alpha2 --> 0.7533
ss3 and alpha5 --> 0.7397
ss5 and alpha4 --> -0.6999
ss and ss2 --> 0.6591
alpha and alpha2 --> 0.6159
alpha5 and ss6 --> 0.6116
ss5 and alpha3 --> -0.5790
ss5 and alpha6 --> -0.5023
ss3 and ss6 --> 0.4804
alpha4 and alpha5 --> -0.4375
e0 and alpha3 --> 0.4083
ss4 and ss5 --> -0.4047
ss3 and alpha4 --> -0.3972
alpha5 and alpha6 --> 0.3827
alpha3 and alpha6 --> 0.3498
ss3 and ss5 --> -0.3278
amp and ss3 --> 0.3209
ss4 and ss6 --> 0.3181
alpha and alpha3 --> 0.3100
alpha2 and alpha3 --> 0.3045
ss4 and alpha3 --> 0.2948
amp and ss5 --> 0.2820
ss2 and alpha6 --> 0.2745
ss and ss3 --> 0.2627
ss2 and ss3 --> 0.2626
amp and alpha6 --> 0.2589
alpha2 and alpha5 --> 0.2581
All other correlations are below 0.25
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