QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: ramkrishna on December 18, 2019, 15:36

Title: Extraction of spin orbit coupling parameter from DFT
Post by: ramkrishna on December 18, 2019, 15:36

Hi,
In the case of DFT+SOC calculation, is it possible to extract the spin-orbit coupling parameter from DFT as calculated by Blonski and Hafner by using DFT in PRB 79, 224418 (2009) (please see the table 1 and 2 in https://journals.aps.org/prb/pdf/10.1103/PhysRevB.79.224418) ??

I will really appreciate your kind reply.

Thanks
Ramkrishna

Title: Re: Extraction of spin orbit coupling parameter from DFT
Post by: ramkrishna on December 24, 2019, 18:40

Hello All,
Is there any possibility to extract the spin-orbit coupling parameter?

Thanks
Ramkrishna

Title: Re: Extraction of spin orbit coupling parameter from DFT
Post by: Petr Khomyakov on December 28, 2019, 19:07

Which exactly SOC parameter do you want to extract? Typically, SOC splitting of bands is extracted directly from a band structure plot.

Title: Re: Extraction of spin orbit coupling parameter from DFT
Post by: ramkrishna on December 29, 2019, 16:57

Hello Petr,
Thank you for your reply. I am basically interested in SOC strength as calculated by DFT in  ttps://journals.aps.org/prb/pdf/10.1103/PhysRevB.79.224418 , not the SOC band splitting. It will be really helpful if it is possible to extract.

Thanks
Ramkrishna

Title: Re: Extraction of spin orbit coupling parameter from DFT
Post by: Petr Khomyakov on January 2, 2020, 14:56

Do you mean the last column in Table 1 in that paper? Please provide definition for this quantity. I am guessing that this is some matrix element or sum of matrix elements for V^SOC_l, but one should define it. If so, note that there is no implemented feature that outputs these matrix elements in QuantumATK. 

Title: Re: Extraction of spin orbit coupling parameter from DFT
Post by: ramkrishna on January 3, 2020, 13:36

Hi Petr,
Thank you for your reply. Yes, it is the last column in table 1 and the sum of matrix elements for V^SOC_l as shown in the eq.

As it is not implemented yet to extract this matrix, is there any indirect way (like some fitting), so that we can evaluate?

Thanks
Ramkrishna

Title: Re: Extraction of spin orbit coupling parameter from DFT
Post by: Petr Khomyakov on January 5, 2020, 10:46

Quote from: ramkrishna on January  3, 2020, 13:36

... the sum of matrix elements for V^SOC_l as shown in the eq.

Which exactly "eq." are you referring to?

Title: Re: Extraction of spin orbit coupling parameter from DFT
Post by: ramkrishna on January 7, 2020, 11:45

V^SOC_l (spin-orbit coupling strength) is the term written in the equation on page 3 of https://journals.aps.org/prb/pdf/10.1103/PhysRevB.79.224418.

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