strange epr line in a dimer simulated spectrum

[binet]

I am trying to simulate with easyspin the powder spectrum of a pair of electrons coupled by dipolar interaction. The simulation exhibits a strange line in the middle of the spectrum, which does seem to have any physical meaning (line indicated by an arrow on the attached file). I do not get this line with XSophe. Is there any reason why this line appears with easyspin?
Here is the code for the simulation:
Sys.S=[1/2 1/2];
Sys.g=[2.0 2.0 2;2.0 2.0 2];
D=180;
Sys.ee=D*[1 1 -2];
Sys.lwpp=1;
Exp.mwFreq=34.113;
Exp.Range=[1200 1240];
EXp.ModAmp=0.2;
Options.nKnots=[1000000 6];
Exp.nPoints=8192;
[Field,Spec]=pepper(Sys,Exp);
figure
plot(Field,Spec)

thanks for your help

Laurent

[Stefan Stoll]

This is an artifact due to an insufficient number of orientations. If you increase them slightly (in Opt.nKnots), then the spectrum is accurate. Here is the code:

Code: Select all

Sys.S = [1/2 1/2];
Sys.g = [2 2];
Sys.ee = 180*[1 1 -2];
Sys.lwpp = 1;
Exp.mwFreq = 34.113;
Exp.Range = [1200 1240];
Opt.nKnots = 100;
[Field,Spec]=pepper(Sys,Exp,Opt);
plot(Field,Spec)

[binet]

Thank you very much Stefan