Mims ENDOR with multiple nuclei

[Nolwenn]

Hello,

I am trying to simulate Mims ENDOR of 14N and 1H using the function saffron on Easyspin.

As I understand it, the simulated Mims ENDOR spectrum of combined 14N and 1H should be the sum of the simulated spectrum of 14N and the simulated spectrum of 1H. It is not what I observe doing the differents simulations.
Could you tell me if I am doing any mistake?

The program I use for the simulation is the following :

clear all;
close all;

Sys.g = [1.921 1.927 2.054];
Sys.Nucs = '1H,14N';
Sys.A = [2;4];
Sys.Q=[0 0;3.6 0.4];
Sys.lwEndor = 0.3;

Exp.ExciteWidth=1/0.016;
Exp.Range = [0 21];
Exp.Sequence='MimsENDOR';
Exp.nPoints=601;
Exp.Field = 0.3588;
Exp.mwFreq=9.6995e9;

[v_s,spc_s]=saffron(Sys,Exp);

Thank you,
Nolwenn

[Stefan Stoll]

Which tau value (Exp.tau) are you using?

[Nolwenn]

I am using a Exp.tau of 0.12.

[Nolwenn]

Sorry, my program is just completely wrong and not very logic!

But the following should be working (3 protons using MIMS ENDOR)

Sys.S=1/2;
Sys.g = [1.921 1.927 2.054];
Sys.Nucs = '1H,1H,1H';
Sys.A = [-4.1 -4.1 0.4 ; -7.5 -7.5 6.9 ; 9.6 9.6 2.37];
Sys.lwEndor = 0.2;

Exp.ExciteWidth=1/0.016; % pulse of 16 ns
Exp.Range = [9 21]; % between 9 and 21 MHz
Exp.Sequence='MimsENDOR';
Exp.tau=0.120; % tau of 120 ns
Exp.nPoints=601;
Exp.Field = 358.8;
Exp.mwFreq=9.699519;

[v_s,spc_s]=saffron(Sys,Exp);
plot(v_s,spc_s);

Isn't the simulation spectrum supposed to be the sum of individual signal for each proton?
It is not the case for me here. I am wondering if I am doing something wrong or if I don't understand something well?

Thank you,
Nolwenn

[Stefan Stoll]

This appears to be a bug. We'll look into this.

Meanwhile, use Opt.ProductRule = 1, which works correctly.

[Nolwenn]

Ok. Thank you very much for your answer.
Nolwenn

[Stefan Stoll]

This bug is fixed in version 5.0.21. It is available on the website.