ESEEM simulation problem

[YJkim]

Hello,
I'm an EASYSPIN beginner, and I have a problem when I try to do ESEEM simulation using "saffron".

first of all, I got M(IV) g-tensor value as g = [2.613 2.113 2.030], through "pepper".
and, I tried to simulate the 14N ESEEM spectra using saffron at several magnetic fields.
but I couldn't get the simulated spectrum at specific magnetic field. (at 1200 mT with 33.986 GHz)

How to I solve the problems?
Thank you in advance.

Code: Select all

clc,clear,clf;

Exp.Sequence = '3pESEEM';
Exp.nPoints = 256;
Exp.dt = 24*0.001;
Exp.T = 80*0.001;
Exp.mwFreq = 33.986;
Exp.Field = 12000*0.1;
Exp.tau = 200*0.001;
Exp.ExciteWidth = 1000/32;

Sys.Nucs = '14N';
Sys.g = [2.613 2.113 2.030];
Sys.A = [3.1 4.8 2.3];
Sys.Q = [4.9 0.1]; 

saffron(Sys,Exp);

[Matt Krzyaniak]

You need to either increase your excitation width or move the field/frequency. Where you are trying to simulated the ESEEM is just outside the spectrum.

Code: Select all

clear
Sys.S = 1/2;
Sys.g = [2.613 2.113 2.030];

Exp.mwFreq = 33.986;

pepper(Sys,Exp)

The highfield feature is at 1198 mT and your excitation width is ~1 mT.

[YJkim]

Thank you for your explanation!
1. By the way, could I ask such silly questions? How to I get the information of excitation width(~1 mT) from the simulated spectrum of attached code?
2. How much can I use the increased excitation width? Is there any limitation for the range?
Thank you in advance.

[Matt Krzyaniak]

1. You calculated your excitation width in MHz Exp.ExciteWidth = 1000/32; so then just use the built in function mhz2mt(1000/32) to get an estimate of your excitewidth in field units.

2. With respect to increasing the bandwidth of your excitation, that is experimentally determined. However you do need to ask if everything else(field and recorded frequency) is properly calibrated or if the g-values you provided are correct. Since based on the values you were using you were trying to simulate the ESEEM outside of the spectral range. The easy check would be to just perform an echo detected field sweep at the same time you collect the ESEEM.

[YJkim]

I really appreciate your time.