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Fitting 5-DSA EPR Spectrum

Posted: Wed Oct 16, 2024 4:27 am
by giosot75

Hi,

I am a new EPR and EASYSPIN user, I have been trying to fit 5-DSA EPR spectra.
This is the initial (very basic) script,

[B, spc] = eprload('Complex_1_10_5_DSA_150scan_1.spc');

Exp.mwFreq = 9.87; % GHz
Exp.Range = [min(B), max(B)];

Sys0.g = [2.009, 2.006, 2.003]; % g-values
Sys0.Nucs = '14N'; % Nitrogen nucleus
Sys0.A = [18, 18, 93]; % Hyperfine constants (MHz)
Sys0.lw = 1; % Linewidth (mT)
Sys0.logtcorr = -9; % Log correlation time

SysVary.g = [0.001, 0.001, 0.001]; % Vary g-values
SysVary.A = [3, 3, 20]; % Vary hyperfine constants
SysVary.lw = 0.3; % Vary linewidth
SysVary.logtcorr = 1; % Vary log correlation time

esfit(spc, @chili, {Sys0, Exp}, {SysVary});

What I am getting is only a straight line, whatever changes I might try to apply.

I would appreciate any suggestions on what I am doing wrong, I am attaching an example of 5-DSA spectra files.


Re: Fitting 5-DSA EPR Spectrum

Posted: Thu Oct 17, 2024 3:09 pm
by Stefan Stoll

I think you forgot to convert the loaded field vector from gauss to millitesla:

Code: Select all

B = B/10;  % G -> mT

Also, according to the parameter file, the microwave frequency is 9.78 and not 9.87 GHz.


Re: Fitting 5-DSA EPR Spectrum

Posted: Fri Oct 18, 2024 4:01 am
by giosot75

Yes indeed, it worked magic!
Thank you very much,

Kind regards

Giorgos