EPR absorption spectra

[komijani]

I am trying to simulate a coupled spin system:
Sys.S = [6 1/2];
Sys.g = [1.5 1.5 1.5; 2 2 2];
Sys.B2 = [0 0 -1000000 0 0; 0 0 0 0 0];
Sys.ee =-3500; % MHz

When I tried simulating the powder spectra I noticed that upon rotating the field, the transition changes from [1 2] to [1 3] and there is a dip right at the field position where this happens (please see attached). I am not quiet sure if this is real and if it is not real, how I can fix the problem.

Thanks

[Stefan Stoll]

All is correct here. At that particular orientation, there is a level anticrossing, and the states 2 and 3 exchange their character.