Spin-spin interaction

[Geraldine]

Hi,

I have been using the Sys.ee function to simulate spin-spin interaction in my system. For example, I wrote:
Sys.S = [1 1];
Sys.g = [2.0004 ; 2.0004];
Sys.lwpp = 0.5;
Sys.ee = [1 1 2]*270
It fits well the experimental data but I am not sure about the meaning of [1 1 2]*270. Can you help me ? Does it mean that the interaction is worth 2*270=540 MHz ?
Thank you very much for your help,
Cheers,
Geraldine

[Stefan Stoll]

Sys.ee includes all forms of electron-electron interactions, no matter what the physical origin is.
Check out the corresponding ES documentation.

Did you mean [-1 -1 2]*270? If yes, this is just the through-space dipolar coupling between two electron spins,
aligned along the z axis.

[Geraldine]

No, I really meant [1 1 2]*270 ...
What about the value of the coupling ? Is it 540 MHz ?
Thanks,

[Matt Krzyaniak]

No, I really meant [1 1 2]*270 ...
What about the value of the coupling ? Is it 540 MHz ?
Thanks,

Code: Select all

Jiso = sum([1 1 2]*270)/3 = 360
Jdip  = [1 1 2]*270 - Jiso = [ -90 -90 180] = 90*[-1 -1 2] 

So you have a 360 MHz isotropic(Heisenberg exchange) coupling and a 90 MHz dipole coupling.

[Geraldine]

Great !
Many thanks !!!!!