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Posted: **Wed Nov 11, 2015 5:17 am**

Dear friends.

I am trying to fit a Duroquinone spectrum. But I am having problems to write the number of atomic species. Its molecule has 12 H and 4 C (mixed between 12C and 13C).
I wrote:

Sys0.Nucs = '1H,(12,13)C';
Sys0.A =[5.6 3.1];
Sys0.Abund = {1,[0.99 0.01]};
Sys0.n = [12 4];

The easyspin returns the following message:

??? Error using ==> isotopologues at 149
Cannot compute isotope patterns for equivalent nuclei.

What would be the solution? Am I using a wrong sintax?

Thanks.

Posted: **Wed Nov 11, 2015 7:52 am**

garlic is not setup to take into account isotope mixtures of equivalent nuclei. And unless you're moderately isotope enriched, the probability of having multiple 13C on the same molecule is negligible. So what you'd ideally want to do is just assume a single 13C and scale up your abundance by the number of carbons. So you'd get code that looks like:

Code: Select all

clear
Sys.S = 1/2;
Sys.Nucs = '1H,(12,13)C';
Sys.A =[5.6 3.1];
Sys.n = [12 1];
Sys.Abund = {1,[0.96 0.04]};
Sys.lwpp = 0.01;

Exp.mwFreq = 9.4; 
Exp.Range = [333 338];
Exp.nPoints = 2048;

garlic(Sys,Exp);

If you're moderately enriched such that you have a some significant probability of having multiple 13C present on your molecule your best bet is calculate the spectra for various numbers of 13C and sum them together scaled by the probability.

Posted: **Wed Nov 11, 2015 1:11 pm**

Dear Matt Krzyaniak.

Your suggestion works.

Thank you for your attention.

EasySpin forum

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How to set Sys0.n for isotopes?

Re: How to set Sys0.n for isotopes?

Re: How to set Sys0.n for isotopes?