problem with resfields

[Hui18]

Hi:

I am using resfields in EasySpin, and it seems that resfields is not finding all the transitions that should occur.

In the code attached, resfields finds transitions [11 12;10 12;11 13]. But I found another transition [10 13] that should be there and is missing.

Is there a potential bug somewhere and is there a way to fix the problem?

Thank you very much in advance for your help!

[Stefan Stoll]

When I run your script, I get transitions that include the 10-13. Can you check?

[Hui18]

Thanks for your reply!

May I know which version of EasySpin are you using? I am using EasySpin 5.0.2 with Matlab R2013b. This is the list of transitions that I get.
trans =

4 5
4 5
4 5
4 5
6 7
6 7
6 7
6 7
8 9
8 9
8 9
8 9
8 9
10 12
11 12
11 13
14 17
17 18
20 21
20 21
22 23
22 25
24 25
24 25
25 26
25 26
35 36
35 36
37 38
37 38
38 41
46 49
48 49
51 54
51 54
51 55
51 55
52 54
52 54
52 55
52 55
52 55
53 54
53 54
53 55
54 57
56 57
56 57
56 57

[Matt Krzyaniak]

Odd, running your script as posted I also get the 10-13 transition. MATLAB 2015a
You're also missing a 52-54 and 53-54 transition.

A total of 52 transitions

Running the script on MATLAB 2012a, I get 50 transitions.

You're reporting 49 transitions.

[Stefan Stoll]

The 10-13 transition is about 1e-4 times weaker than the most intense transition, 8-9. Therefore, you won't see it in the EPR spectrum, even though the microwave quantum matches the energy difference.

EasySpin uses Opt.Threshold to select transitions based on their calculated intensity, relative to the maximum intensity. It seems like 10-13 falls just below the default threshold (1e-4). Lower Opt.Threshold to 1e-5 or 1e-6, and you should get more transitions, including 10-13.

Your system is very complex (use levelsplot to look at the level diagram!). It is not unexpected that numerical noise (different in different Matlab versions) is going to affect these essentially forbidden transitions.

[Hui18]

Hi:

I modified the angles in the program attached.

Running the commented line with transition from 11 to 12, I got a peak at about 7.5T with very high amplitude(Amp). But after changing into all transitions, resfields lost the peak entirely. Could it be because of the same problem that I reported last time?

Thank you very much!