Forbidden transitions with large intensities
Dear Prof. Stoll
I am trying to simulate a rigid CW spectrum for Mn (+2) acquired at 20 K. It has doublet forbidden transitions with significant intensities at X Band (See experimental data below ) that are hard to simulate because esfit is struggling to get the intensities right. Obviously my parameters are not right but I started with some published ones.
Your publication states that unless high-field limit is valid and intensities are above a certain threshold, Easyspin will not waste time on forbidden transition intensity calculations (paraphrased!). Can you comment on the approach to simulate forbidden transitions when they are very significant such as in this spectrum at X band. Any chance that Easyspin erroneously discards such transitions thus making spectral simulation difficult ? Below is the script and the experimental data are attached in case you wanna talk a look at the simulation. Let me know for any feedback or comment. Cheers !
clear, clc, clf
[field, intensity, parameters]=eprload('MnCl2_water_20K_CW');
field= field (260:737); % truncated data
intensity = intensity (260:737); %truncated data
plot(field, intensity)
center = length(field)/2; % approximate center after truncating data above
center= field(center)/10; % convert to mT
width = field (end)-field(1); % approximate width after truncating data
Sys.Nucs = '55Mn';
Sys.S= 5/2;
Sys.A = [253 228 233];
Sys.g = [2.010 2.0571 1.907];
Sys.lwpp= 1.4;
Sys.HStrain = [2.71 10.22 57.41];
Sys.D = [40.51 7.0];%these are just starting values (not known )
Sys.DStrain = [0.51 1.50];
initial = field (1)/10;
final = field (end)/10;
Exp.mwFreq = parameters.MWFQ/1e9;
Exp.Range = [initial, final];
Opt.Method = 'matrix';
Exp.nPoints= length(intensity);
Vary.A = [3 3 3];
% Vary.g = [0.01 0.05 0.05];
Vary.lwpp =0.5;
Vary.HStrain = [1 5 3];
Vary.D= [0.5 1];
Vary.DStrain = [0.5 0.5];
[simulation_x, simulation_y]=pepper (Sys,Exp);
plot(simulation_x, simulation_y/max(simulation_y), 'r');hold on
plot(field/10, intensity/max(intensity), 'k')
esfit(@pepper,intensity,Sys,Vary,Exp, Opt) % not outputting simulation yet