EasySpin forum

Hi,

I have some troubles understanding Pepper output, although I am not sure if this is a bug. The problem is evident when simulating a spin system with some partially forbidden transitions (see example below). levelsplot outputs significantly different transition probabilities, while pepper provides the same signal intensity of both transitions. Does this mean that pepper ignores transitions probabilities?


Temperature = 10;
FieldRange = [1 400];
mwFreq = 3.6;
Threshold = 0.001;

% Experimental parameters
Exp.Range = FieldRange;
Exp.mwFreq = mwFreq;
Exp.Temperature = Temperature;
Exp.Harmonic = 0;
Exp.nPoints = 100000;
Exp.CrystalOrientation = [0 0 0];

% Spin System
Sys.S = 1/2;
Sys.g = 2.0023;
Sys.Nucs = '125Te';
Sys.A = 3500;
Sys.lwpp = [0 0.2];

figure;
pepper(Sys,Exp);

figure;
Par.PlotThreshold = Threshold;
levelsplot(Sys,[0 0],FieldRange,mwFreq,Par);


Best wishes,
Mantas

I figured that in levelsplot the Freq2Field is set to zero when running resfields. It appears as the reason for the difference between pepper and levelsplot. In the documentation of pepper it is suggested to never change the default value Freq2Field. I do not understand why in some cases this conversion factor is considered and others not. I just want to share what I found and maybe get notified when there is answer from others.

Freq2Field turns on the inclusion of the 1/g (Aasa-Vangaard) factor into the line intensity. This is only relevant when simulating field-swept spectra. For frequency-swept spectra, it is irrelevant, and it is omitted by pepper in this case.