Esfit fitting problem

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arijithazari
Newbie
Posts: 3
Joined: Fri Mar 05, 2021 2:43 pm

Esfit fitting problem

Post by arijithazari »

Hi,
I am new to easyspin! I have been trying to fit epr data, however simulation of the parameters is taking way too long than expected and I have been getting following error after a while

'** Spectrum exceeds sweep range. Artifacts at upper limit possible.
** Spectrum exceeds sweep range. Artifacts at upper limit possible.'

Please suggests!

Thank you!

Attachments
CuII_CuII_fused_solid_mod.m
(2.04 KiB) Downloaded 112 times
thanasis
Local Expert
Posts: 242
Joined: Thu Jan 21, 2016 6:28 am
Location: Strasbourg

Re: Esfit fitting problem

Post by thanasis »

You don't include the experimental spectrum, so we cannot run the script, but some comments can be made:
-The problem's Hilbert dimension is (2 * 1 + 1)*(2 * 3/2 + 1)2 = 48. It's not excessive, but it isn't negligible either.
-As for the message, during the fit some resonances appear outside your experimental range. This might not be a serious problem, but if you want to get rid of it maybe try a spectrum over a broader region.

arijithazari
Newbie
Posts: 3
Joined: Fri Mar 05, 2021 2:43 pm

Re: Esfit fitting problem

Post by arijithazari »

Hello,
Sorry, I forgot to attach the epr file, please find the attachment.
Thanks for the suggestion. But, I did try to run the simulation over wider experimental range. But I still have the same problem.

Thank you again.

Attachments
20200714_161637116_SDC281_CuFusedSub_e_10_tmp_-175C.zip
(1.02 MiB) Downloaded 114 times
thanasis
Local Expert
Posts: 242
Joined: Thu Jan 21, 2016 6:28 am
Location: Strasbourg

Re: Esfit fitting problem

Post by thanasis »

Yes, overall it was slow, but not shockingly so. Remember, it is a powder spectrum, so you need to integrate over a large number of orientations. Maybe you can decrease the number of nodes on your spherical grid for the initial fits.

Also, I got no alert, though I did not let it turn for too many iterations. It may be that during the fitting process some iterations give parameters that lead to off-range resonances. I didn't see anything worrisome, though.

arijithazari
Newbie
Posts: 3
Joined: Fri Mar 05, 2021 2:43 pm

Re: Esfit fitting problem

Post by arijithazari »

Ok, thank you very much for your suggestions. I have taken into account all the points now, it is running fine.

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