Large Hyperfine Coupling and Garlic

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joe.zadrozny
Newbie
Posts: 1
Joined: Sat Aug 13, 2016 5:31 pm

Large Hyperfine Coupling and Garlic

Post by joe.zadrozny »

Hello,

I'm playing around with some ideas in my head and thus I'm trying to do some fast motion simulations of solution spectra at low (2-5 GHz specifically) frequencies with molecules that have large hyperfine coupling interactions. I'm trying to use garlic and it begins to crash when I move to lower frequencies. The position at which the program stops computing spectra depends on the size of the hyperfine coupling interaction: a lower hyperfine coupling enables simulations at lower frequencies. Is the crashing at lower frequencies a bug? Maybe I am using the wrong program and chili would be better?

Thank you for your time!
-Joe

Here's the code i'm using.

Code: Select all

Sys1.S = 0.5;
Sys1.lwpp = 5;
Sys1.Nucs = '165Ho';
Sys1.A = [1122];
Sys1.g = [3.277];
Exp.mwFreq = 4;
Exp.CenterSweep = [450 900];
Exp.Temperature = 10;
Exp.Mode = 'perpendicular';
Exp.ModAmp = 3;
garlic(Sys1,Exp)
Matt Krzyaniak
EasySpin Guru
Posts: 153
Joined: Tue Jul 22, 2014 11:01 am
Location: Northwestern University

Re: Large Hyperfine Coupling and Garlic

Post by Matt Krzyaniak »

The algorithm used to calculate the peak positions in garlic runs into problems with extremely large hyperfine couplings, especially at the low frequencies you're using. You're better off using pepper, it does a full matrix diagonalization and can more easily handle the weird stuff that occurs when the hyperfine is on the same order as the electron Zeeman.

But garlic does need to have better error messages for these situations.
Stefan Stoll
EasySpin Creator
Posts: 1041
Joined: Mon Jul 21, 2014 10:11 pm
Location: University of Washington

Re: Large Hyperfine Coupling and Garlic

Post by Stefan Stoll »

It's on our to-do list to improve the handling of this situation.
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