Quadrupolar term

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Eufemio
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Posts: 9
Joined: Sat Nov 01, 2014 3:35 pm

Quadrupolar term

Post by Eufemio »

Dear Stefan,

I have a question regarding the quadrupolar term in easyspin. I simulated the Zeeman diagram from a paper of a Tb(III) ion, including the quadrupolar interaction. For some reason in order to obtain the simulation as in the paper I have to multiply the quadrupolar value given in the paper exactly by 4. (the quadrupolar term in the paper is: P{Iz^2 1/3I(I+1)})

I thought the quadrupolar term in easyspin and the paper were similar. Do you have any idea what is the reason for this?

Thanks in advance!

Best wishes,

Eufemio
Stefan Stoll
EasySpin Creator
Posts: 1073
Joined: Mon Jul 21, 2014 10:11 pm
Location: University of Washington

Re: Quadrupolar term

Post by Stefan Stoll »

Please post a short script and the link to the paper, so we can have a look.
Eufemio
Newbie
Posts: 9
Joined: Sat Nov 01, 2014 3:35 pm

Re: Quadrupolar term

Post by Eufemio »

Sure, this is the link to the paper (http://onlinelibrary.wiley.com/doi/10.1 ... 8/abstract). The Zeeman diagram is the one in Figure 3. The Script is:

Sys.g = [3/2];
Sys.S = [6];
Sys.Nucs = '159Tb';
Sys.A = [A]*clight/1e4;
Sys.Q = 4*[Q]*clight/1e4; %To reproduce the Zeeman diagram I have to multiply the Quadrupolar term by 4!
Sys.B2 = alpha*[0 0 B20 0 0]*clight/1e4;
Sys.B4 = beta*[B44 0 0 0 B40 0 0 0 0]*clight/1e4;
Sys.B6 = gamma*[0 0 B64 0 0 0 B60 0 0 0 0 0 0]*clight/1e4;

Alpha, beta and gamma are constants related to the Tb ion.

Cheers
Stefan Stoll
EasySpin Creator
Posts: 1073
Joined: Mon Jul 21, 2014 10:11 pm
Location: University of Washington

Re: Quadrupolar term

Post by Stefan Stoll »

Please post a self-containing script that gives all the constants and also the function call so that we can run it. Thanks!
Eufemio
Newbie
Posts: 9
Joined: Sat Nov 01, 2014 3:35 pm

Re: Quadrupolar term

Post by Eufemio »

Attached is the script file.
Best,
Eufemio
Attachments
Terbium.m
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Stefan Stoll
EasySpin Creator
Posts: 1073
Joined: Mon Jul 21, 2014 10:11 pm
Location: University of Washington

Re: Quadrupolar term

Post by Stefan Stoll »

This is correct. If you give a single number for Sys.Q, EasySpin understands it as e^2Qq/h.

The term given in the paper, P*(Iz^2-I(I+1)/3), corresponds to P/3*(-Ix^2-Iy^2+2*Iz^2). If you look at the EasySpin reference page on the nuclear quadrupole interaction, the prefactor P/3 is equal to e^2Qq/h/(4I*(2I-1)). The denominator in the last expression is 12, so this means P/3 = e^2Qq/h/12. From this e^2Qq/h = 4*P.
Eufemio
Newbie
Posts: 9
Joined: Sat Nov 01, 2014 3:35 pm

Re: Quadrupolar term

Post by Eufemio »

Perfect, thanks for the explanation Stefan!
Cheers,
Eufemio
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