[QE-users] How to extract the px, py, pz, dz2, ....contributions with SOC from projdos out
Pietro Davide Delugas
pdelugas at sissa.it
Mon Jul 5 12:41:45 CEST 2021
P.S. the trick works easily only in the case that the relativistic
pseudo-potential is norm-conserving.
On 7/5/21 12:13 PM, Pietro Davide Delugas wrote:
> Dear Elie
> keeping in mind the caveat of Thomas you could in fact "cheat"
> projwfc in projecting your eigenstates into the non-relatistic atomic
> states labeled with l and the spin (up or down along z).
> You just have to open the xml restart file ( the one inside the
> prefix.save directory) look for the output element and, inside it,
> the magnetization element,
> there change the <spinorbit> element from true to false.
>
> hope this helps
> Pietro
>
>
>
>
>
> On 7/4/21 8:37 PM, Elio Physics wrote:
>> Dear Thomas,
>>
>> Thank you for the generous and detailed answer. Indeed, what made me
>> confused is that some papers still use the terminology "dz2' ,for
>> example, even in the presence of the SOC. I will definitely be
>> looking at the papers you suggested to decide which option I will
>> adopt for the discussion I need.
>>
>> Regards
>>
>> ------------------------------------------------------------------------
>> *From:* Thomas Brumme <tbrumme at msx.tu-dresden.de>
>> *Sent:* Sunday, July 4, 2021 10:24 AM
>> *To:* Quantum ESPRESSO users Forum
>> <users at lists.quantum-espresso.org>; Elio Physics <Elio-Physics at live.com>
>> *Subject:* Re: [QE-users] How to extract the px, py, pz, dz2,
>> ....contributions with SOC from projdos out
>>
>> Dear Elie,
>>
>>
>> The short answer is: You can't!
>>
>>
>> Spin-orbit interaction couples the orbital angular momentum with the
>> spin momentum and thus neither l or s are good quantum number
>> anymore. You now have to use the total angular momentum J. Sure, a
>> lot of people still use the nomenclature from the non-SOC
>> calculations, such as speaking in the case of 2D TMDCs of dz² states
>> at the K point, but strictly speaking this is not correct. If you
>> really want to understand the relation between J and L in detail, I
>> can recommend the paper by Andrea Dal Corso and Adriano Mosca Conte,
>> Phys. Rev. B 71, 115106 (2005)
>> (https://link.aps.org/doi/10.1103/PhysRevB.71.115106
>> <https://link.aps.org/doi/10.1103/PhysRevB.71.115106>) which nicely
>> shows which spherical harmonics are included in which spin-angle
>> functions for which total angular momentum j. If I remember this
>> correctly (some time ago that I did this and I can't find the table
>> anymore) the states with higher mj (+-3/2 and +- 5/2) have more
>> in-plane characterfor both j=3/5 and j=5/2 (i.e., the contain terms
>> with spherical harmonics which are usually combined such that the
>> result is in the xy-plane) while the states with mj=+-1/2 have more
>> out-of-plane character (z direction). But I could be wrong here since
>> I don't have the details anymore.
>>
>>
>> The only option for you - if you don't want to check the paper or if
>> this is too much and if nobody else comments here - is to do a
>> non-SOC calculation and then hope that SOC is not mixing states too
>> much and you can still call the result, e.g., dz² like. OR you plot
>> the corresponding wave function in real space and decide by "looking"
>> at the form of |psi|².
>>
>>
>> Regards
>>
>>
>> Thomas
>>
>>
>>
>> P.S.: another detail concerning, e.g., the states at K in a WS2
>> monolayer - is this your system? :)
>>
>> The states are not simple split into spin up and spin down even if a
>> lot of people use this nomenclature. For the valence band the two
>> SOC-split bands are to nearly 100% spin up or down but not for the
>> conduction band where you won't have states which are 100% up or
>> down, even if there is no in-plane contribution... Some details can
>> also be found here:
>> https://link.aps.org/doi/10.1103/PhysRevB.101.235408
>> <https://link.aps.org/doi/10.1103/PhysRevB.101.235408>
>>
>>
>> On 7/4/21 6:52 AM, Elio Physics wrote:
>>> Dear all,
>>>
>>> I am studying the contribution of the orbitals to the bands of a
>>> structure, in the presence of spin orbit coupling. At the beginning
>>> of the projwfc.x output file, I got:
>>>
>>> state # 1: atom 1 (S ), wfc 1 (l=0 j=0.5 m_j=-0.5)
>>> state # 2: atom 1 (S ), wfc 1 (l=0 j=0.5 m_j= 0.5)
>>> state # 3: atom 1 (S ), wfc 2 (l=1 j=0.5 m_j=-0.5)
>>> state # 4: atom 1 (S ), wfc 2 (l=1 j=0.5 m_j= 0.5)
>>> state # 5: atom 1 (S ), wfc 3 (l=1 j=1.5 m_j=-1.5)
>>> state # 6: atom 1 (S ), wfc 3 (l=1 j=1.5 m_j=-0.5)
>>> state # 7: atom 1 (S ), wfc 3 (l=1 j=1.5 m_j= 0.5)
>>> state # 8: atom 1 (S ), wfc 3 (l=1 j=1.5 m_j= 1.5)
>>> .
>>> .
>>> .
>>> state # 39: atom 5 (W ), wfc 3 (l=2 j=1.5 m_j=-1.5)
>>> state # 40: atom 5 (W), wfc 3 (l=2 j=1.5 m_j=-0.5)
>>> state # 41: atom 5 (W), wfc 3 (l=2 j=1.5 m_j= 0.5)
>>> state # 42: atom 5 (W), wfc 3 (l=2 j=1.5 m_j= 1.5)
>>> state # 43: atom 5 (W ), wfc 4 (l=2 j=2.5 m_j=-2.5)
>>> state # 44: atom 5 (W ), wfc 4 (l=2 j=2.5 m_j=-1.5)
>>> state # 45: atom 5 (W), wfc 4 (l=2 j=2.5 m_j=-0.5)
>>> state # 46: atom 5 (W), wfc 4 (l=2 j=2.5 m_j= 0.5)
>>> state # 47: atom 5 (W), wfc 4 (l=2 j=2.5 m_j= 1.5)
>>>
>>> The l=1 wavefunctions are the p contributions. But How can we
>>> specifically identify which one is px, py and pz?
>>> Similary, how to identify which ones of the 10 d orbitals are the
>>> dz^2 for example
>>>
>>> regards
>>>
>>> Elie
>>> Federal Universiy of Rondonia
>>> Brazil
>>>
>>> _______________________________________________
>>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu <http://www.max-centre.eu>)
>>> users mailing listusers at lists.quantum-espresso.org <mailto:users at lists.quantum-espresso.org>
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>> --
>> Dr. rer. nat. Thomas Brumme
>> Theoretical chemistry
>> TU Dresden - BAR / II49
>> Helmholtzstr. 18
>> 01069 Dresden
>>
>> Tel: +49 (0)351 463 40844
>>
>> email:thomas.brumme at tu-dresden.de <mailto:thomas.brumme at tu-dresden.de>
>>
>> _______________________________________________
>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
>> users mailing listusers at lists.quantum-espresso.org
>> https://lists.quantum-espresso.org/mailman/listinfo/users
>
>
>
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