Re: [QE-users] Requesting Help With Spin Orbit Coupling Spin-Separated Bands Extraction
Dear Pratyush Manocha, > I'm repeating this just for clarity. So, "lsigma = 1,2,3" would give me > the expectation values of the spin operator along the cartesian > coordinate axes, x, y, and z, right? Right. > How would I go about doing this? Is it possible to do this on Quantum > Espresso itself? I don't think doing this would hold any value because > the spin-up direction is also changing as the spin axis is changing. > However, if the spin vector in the band is aligned in the local spin-up > direction at all points along the k-path, it would be considered the > spin-up band. So, I would like to learn how to compute it to increase my > understanding of the system. It doesn't. But since "lsigma" gives you the three orthogonal vector components, by using regular vector properties you can obtain the polar and azimuthal angles. As I said in my previous e-mail, if you are interested in identifying spin polarized bands, using a color scale to express spin components values on a band structure plot should give you the information you need without much hassle. Best regards, Luiz Gustavo Silveira Assistant professor, Department of Physics - Federal University of Paraná Curitiba - Brazil Em Qua, Março 22, 2023 8:08 pm, Manocha, Pratyush escreveu: > Dear Professor Luiz, > > > Thank you for your response. I have a couple of more questions. > > >> It gives you the expectation values of the spin operator. >> > >> Simply put, "lsigma = 1,2,3" gives you the three orthogonal components >> of the spin vector. > > I'm repeating this just for clarity. So, "lsigma = 1,2,3" would give me > the expectation values of the spin operator along the cartesian > coordinate axes, x, y, and z, right? > >> You could, in principle, determine which direction this is and define >> locally what is spin up and spin down, I don't know if it's worth it, >> though. > > How would I go about doing this? Is it possible to do this on Quantum > Espresso itself? I don't think doing this would hold any value because > the spin-up direction is also changing as the spin axis is changing. > However, if the spin vector in the band is aligned in the local spin-up > direction at all points along the k-path, it would be considered the > spin-up band. So, I would like to learn how to compute it to increase my > understanding of the system. > >> But if the bands are splitted and spin-polarized you will end up with a >> graph showing something similar to spin-up and spin-down bands. > Got it. > > > Regards, > Pratyush Manocha > Graduate Student | M.S. Electrical & Computer Engineering > School of Electrical and Computer Engineering > Georgia Institute of Technology > [cid:55e08a0f-cc73-4d36-8b82-45ea4b522d9d] > > From: Luiz Gustavo Davanse da Silveira > Sent: Monday, March 20, 2023 16:25 > To: Manocha, Pratyush > Cc: users@lists.quantum-espresso.org > Subject: Re: [QE-users] Requesting Help With Spin Orbit Coupling > Spin-Separated Bands Extraction > > > Dear Pratyush Manocha, > > > Now I'm the one who has to apologize about a delayed response. > > >> Thank you for informing me about the "lsigma" keyword. While it doesn't >> solve my problem of segregating spin-up bands from spin-down ones, it >> gives me the expectation values of the total angular momentum along the >> x, y, and z axes, right? > > It gives you the expectation values of the spin operator. > > >> I tried extracting the data for GaAs, and I noticed from the results >> that often, the expectation values are values other than 0.5, 0, and >> -0.5; >> does this mean that, at these points, the band has a mix of both spin-up >> and spin-down electrons? > > Well, you might find sources that describe it like that, but, as I see > it, in noncollinear calculations each electronic state can have its own > spin quantization axis. Therefore, global spin-up and spin-down states may > not be a good description. Rather, depending on the complexity of your > system, at each k-point of a given band spins may be align in a particular > direction. You could, in principle, determine which direction this is > and define locally what is spin up and spin down, I don't know if it's > worth it, though. Simply put, "lsigma = 1,2,3" gives you the three > orthogonal components of the spin vector. If you take the modulus, the > result should be 0.5 (or close to it). > >> Another question I had is: when you say that I can color the bands >> according to the spin values like a fatband plot, do you mean that each >> band would individually be coloured from "colour a" to "colour b" based >> on the spin values at the different k points along the chosen >> "k-path?" >> > > Exactly. This form of showing the data might not be useful if bands are > degenerate. But if the bands are splitted and spin-polarized you will end > up with a graph showing something similar to spin-up and spin-down bands. > > > Best regards, > > > Luiz Gustavo Silveira > Assistant professor, Department of
Re: [QE-users] Requesting Help With Spin Orbit Coupling Spin-Separated Bands Extraction
Dear Pratyush Manocha, Now I'm the one who has to apologize about a delayed response. > Thank you for informing me about the "lsigma" keyword. While it doesn't > solve my problem of segregating spin-up bands from spin-down ones, it > gives me the expectation values of the total angular momentum along the > x, y, and z axes, right? It gives you the expectation values of the spin operator. > I tried extracting the data for GaAs, and I noticed from the results that > often, the expectation values are values other than 0.5, 0, and -0.5; > does this mean that, at these points, the band has a mix of both spin-up > and spin-down electrons? Well, you might find sources that describe it like that, but, as I see it, in noncollinear calculations each electronic state can have its own spin quantization axis. Therefore, global spin-up and spin-down states may not be a good description. Rather, depending on the complexity of your system, at each k-point of a given band spins may be align in a particular direction. You could, in principle, determine which direction this is and define locally what is spin up and spin down, I don't know if it's worth it, though. Simply put, "lsigma = 1,2,3" gives you the three orthogonal components of the spin vector. If you take the modulus, the result should be 0.5 (or close to it). > Another question I had is: when you say that I can color the bands > according to the spin values like a fatband plot, do you mean that each > band would individually be coloured from "colour a" to "colour b" based > on the spin values at the different k points along the chosen "k-path?" Exactly. This form of showing the data might not be useful if bands are degenerate. But if the bands are splitted and spin-polarized you will end up with a graph showing something similar to spin-up and spin-down bands. Best regards, Luiz Gustavo Silveira Assistant professor, Department of Physics - Federal University of Paraná Curitiba - Brazil Em Qui, Março 9, 2023 11:47 pm, Manocha, Pratyush escreveu: > Dear Professor Luiz, > > > I apologize for my delayed response; I had exams to appear for. > > > Thank you for informing me about the "lsigma" keyword. While it doesn't > solve my problem of segregating spin-up bands from spin-down ones, it > gives me the expectation values of the total angular momentum along the > x, y, and z axes, right? > > I tried extracting the data for GaAs, and I noticed from the results that > often, the expectation values are values other than 0.5, 0, and -0.5; > does this mean that, at these points, the band has a mix of both spin-up > and spin-down electrons? > > Another question I had is: when you say that I can color the bands > according to the spin values like a fatband plot, do you mean that each > band would individually be coloured from "colour a" to "colour b" based > on the spin values at the different k points along the chosen "k-path?" > > Thank you very much for helping me with this! > > > Regards, > Pratyush Manocha > Graduate Student | M.S. Electrical & Computer Engineering > School of Electrical and Computer Engineering > Georgia Institute of Technology > > From: Luiz Gustavo Davanse da Silveira > Sent: Thursday, February 16, 2023 14:03 > To: Manocha, Pratyush > Cc: users@lists.quantum-espresso.org > Subject: Re: [QE-users] Requesting Help With Spin Orbit Coupling > Spin-Separated Bands Extraction > > > Dear Pratyush Manocha, > > > I believe the spin_component variable doesn't work with noncollinear > calculations. You can however use the lsigma variable in bands.x input to > get the spin components at each k-point for every band. Then, for > instance, you can use this information to color the band plot according > to spin values (like a fatbands plot). > > Best Regards, > > > Luiz Gustavo Silveira > Assistant professor, Department of Physics - Federal University of Paraná > Curitiba - Brazil > > > Em Seg, Dezembro 19, 2022 7:22 pm, Manocha, Pratyush escreveu: > >> Dear All, >> >> >> >> I am using QE-7.1 and want to plot the spin-orbit coupled bands for >> Silicon and later on, GaN. I ran a few simulations for Silicon (with a >> fully relativistic pseudopotential obtained from PSLibrary 1.0.0) by >> turning on the "lspinorb" and "noncolin" keywords and specifying a >> non-zero "starting_magnetization" in the "" namecard. The >> simulation runs smoothly, however, when I try to extract the bands for >> just spin-down electrons using "spin_component=2" in the input file >> given to the bands.x code, it returns the following error: Error in >> routine punch_bands (1): incorrect spin_component???. >> >> I went through the archive and also tried simulating with various >> different keyword combinations using "nspin" and "lspinorb", and I found >> that "lspinorb" requires non-colinear spin vectors whereas "nspin=2" >> requires colinear spins, therefore, they would not work simultaneously. >> As a result, I can not use the
Re: [QE-users] Requesting Help With Spin Orbit Coupling Spin-Separated Bands Extraction
Dear Pratyush Manocha, I believe the spin_component variable doesn't work with noncollinear calculations. You can however use the lsigma variable in bands.x input to get the spin components at each k-point for every band. Then, for instance, you can use this information to color the band plot according to spin values (like a fatbands plot). Best Regards, Luiz Gustavo Silveira Assistant professor, Department of Physics - Federal University of Paraná Curitiba - Brazil Em Seg, Dezembro 19, 2022 7:22 pm, Manocha, Pratyush escreveu: > Dear All, > > > I am using QE-7.1 and want to plot the spin-orbit coupled bands for > Silicon and later on, GaN. I ran a few simulations for Silicon (with a > fully relativistic pseudopotential obtained from PSLibrary 1.0.0) by > turning on the "lspinorb" and "noncolin" keywords and specifying a > non-zero "starting_magnetization" in the "" namecard. The > simulation runs smoothly, however, when I try to extract the bands for > just spin-down electrons using "spin_component=2" in the input file given > to the bands.x code, it returns the following error: Error in routine > punch_bands (1): incorrect spin_component???. > > I went through the archive and also tried simulating with various > different keyword combinations using "nspin" and "lspinorb", and I found > that "lspinorb" requires non-colinear spin vectors whereas "nspin=2" > requires colinear spins, therefore, they would not work simultaneously. > As a result, I can not use the "spin_component" keyword in the bands.x > input file to extract the spin separated bands. So my question is: if I > am using "lspinorb=.true." and "noncolin=.true.", is there a way to > extract the spin-up and spin-down conduction and valence bands > separately? > > Any help would be appreciated. > > > Regards, > Pratyush Manocha > Graduate Student | M.S. Electrical & Computer Engineering > School of Electrical and Computer Engineering > Georgia Institute of Technology > [cid:f2b1f8a4-9ef8-4579-9715-844bf6b1658b] > > ___ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] How to compute spin projections?
Dear Thomas, That's exactly what I need, thank you! Good luck with your manuscript! Best Regards, Luiz G. D. Silveira Associate Professor - UFPR - Brazil Em Qua, Março 30, 2022 1:01 pm, Thomas Brumme escreveu: > Dear Luiz, > > > > the correct tool you search is bands.x - if you look at the description > of it, you will find the key word > > lsigma(i), i=1,3 which does the job. Usually, bands.x is used for paths > along high symmetry lines in the BZ but you can also provide a full MP > grid if you want to plot the spin texture in the whole BZ. I actually did > this for a manuscript which is in the still-to-be-finalized stage since > ages... > > Kind regards > > > Thomas > > > > -- > Dr. rer. nat. Thomas Brumme > Theoretical chemistry > TU Dresden - KOE / 103 > Bergstr. 66c > 01069 Dresden > > > Tel: +49 (0)351 463 40844 > > > email: thomas.bru...@tu-dresden.de > > > > > Von: users im Auftrag von Luiz > Gustavo Davanse da Silveira via users > Gesendet: Mittwoch, 30. März 2022 18:07 > An: Lorenzo Paulatto > Cc: Quantum ESPRESSO users Forum > Betreff: Re: [QE-users] How to compute spin projections? > > > Dear Lorenzo Paulatto, > > > Thanks for your reply. Indeed it does. However I would like to have spin > projections in reciprocal space to plot spin-textures, for example. > > Best regards, > Luiz G. D. Silveira > Associate Professor - UFPR - Brazil > > > Em Qua, Março 30, 2022 3:56 am, Lorenzo Paulatto escreveu: > >> I think if you do a non-collinear spin calculation, QE prints the spin >> around each atom on screen., i.e. : >> === >> == >> = >> atom number 1 relative position : 0. 0. 0. charge : 9.813443 >> magnetization : -0.86 0.00 0.00 magnetization/charge: >> -0.09 0.00 0.00 >> polar coord.: r, theta, phi [deg] : 0.000086 90.00 180.00 >> >> === >> == >> = >> >> >> >> -- >> Lorenzo Paulatto - Paris >> On Mar 30 2022, at 4:09 am, Luiz Gustavo Davanse da Silveira via users >> wrote: >> >> >>> Dear QE users and developers, >>> >>> >>> >>> For non-linear calculations VASP print out on the PROCAR file three >>> othogonal spin projections at each k point of each band. Is there an >>> way to obtain the same information from calculations done in QE? >>> >>> Best regards, >>> Luiz G. D Silveira >>> Associate Professor - UFPR - Brazil >>> >>> >>> >>> ___ >>> The Quantum ESPRESSO community stands by the Ukrainian >>> people and expresses its concerns about the devastating effects that >>> the Russian military offensive has on their >>> country and on the free and peaceful scientific, cultural, and >>> economic cooperation amongst peoples >>> ___ >>> Quantum ESPRESSO is supported by MaX >>> (www.max-centre.eu<http://www.max-centre.eu>) >>> users mailing list users@lists.quantum-espresso.org >>> https://lists.quantum-espresso.org/mailman/listinfo/users >>> >>> >>> >> >> > > > ___ > The Quantum ESPRESSO community stands by the Ukrainian > people and expresses its concerns about the devastating effects that the > Russian military offensive has on their > country and on the free and peaceful scientific, cultural, and economic > cooperation amongst peoples > ___ > Quantum ESPRESSO is supported by MaX > (www.max-centre.eu<http://www.max-centre.eu>) > users mailing list users@lists.quantum-espresso.org > https://lists.quantum-espresso.org/mailman/listinfo/users > > ___ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] How to compute spin projections?
Dear Lorenzo Paulatto, Thanks for your reply. Indeed it does. However I would like to have spin projections in reciprocal space to plot spin-textures, for example. Best regards, Luiz G. D. Silveira Associate Professor - UFPR - Brazil Em Qua, Março 30, 2022 3:56 am, Lorenzo Paulatto escreveu: > I think if you do a non-collinear spin calculation, QE prints the spin > around each atom on screen., i.e. : > = > = > atom number 1 relative position : 0. 0. 0. charge : 9.813443 > magnetization : -0.86 0.00 0.00 magnetization/charge: > -0.09 0.00 0.00 > polar coord.: r, theta, phi [deg] : 0.86 90.00 180.00 > > = > = > > > -- > Lorenzo Paulatto - Paris > On Mar 30 2022, at 4:09 am, Luiz Gustavo Davanse da Silveira via users > wrote: > >> Dear QE users and developers, >> >> >> For non-linear calculations VASP print out on the PROCAR file three >> othogonal spin projections at each k point of each band. Is there an way >> to obtain the same information from calculations done in QE? >> >> Best regards, >> Luiz G. D Silveira >> Associate Professor - UFPR - Brazil >> >> >> ___ >> The Quantum ESPRESSO community stands by the Ukrainian >> people and expresses its concerns about the devastating effects that the >> Russian military offensive has on their >> country and on the free and peaceful scientific, cultural, and economic >> cooperation amongst peoples >> ___ >> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >> users mailing list users@lists.quantum-espresso.org >> https://lists.quantum-espresso.org/mailman/listinfo/users >> >> > > ___ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] How to compute spin projections?
Dear Hongyi Zhao, Thanks for your replys. I am answering them all at once. I tried projwfc.x but got only orbital projections. I took a look at the inout documentation and couldn't find an apropriate variable to compute spin projections. Perhaps I am missing something but I can't realize what it would be. I also tried pyprocar but it doesn't support QE non-colinear calculations right now. Best regards, Luiz G. D. Silveira Associate Professor - UFPR - Brazil Em Qua, Março 30, 2022 4:57 am, Hongyi Zhao escreveu: > On Wed, Mar 30, 2022 at 3:49 PM Hongyi Zhao > wrote: > >> >> On Wed, Mar 30, 2022 at 9:56 AM Luiz Gustavo Davanse da Silveira via >> users wrote: >>> >>> Dear QE users and developers, >>> >>> >>> For non-linear calculations VASP print out on the PROCAR file three >>> othogonal spin projections at each k point of each band. Is there an >>> way to obtain the same information from calculations done in QE? >> >> The pyprocar [1] python package is exactly designed for this type of >> work. See the following description on its official GitHub repository for >> more details: >> >> ``` >> PyProcar is a robust, open-source Python library used for pre- and >> post-processing of the electronic structure data coming from DFT >> calculations. PyProcar provides a set of functions that manage data >> obtained from the PROCAR format. Basically, the PROCAR format is a >> projection of the Kohn-Sham states over atomic orbitals. That projection >> is performed to every k-point in the considered mesh, every energy band >> and every atom. PyProcar is capable of performing a multitude of tasks >> including plotting plain and spin/atom/orbital projected band structures >> and Fermi surfaces- both in 2D and 3D, Fermi velocity plots, unfolding >> bands of a super cell, comparing band structures from multiple DFT >> calculations, plotting partial density of states and generating a k-path >> for a given crystal structure. >> >> Currently supports: >> >> >> VASP >> Elk >> Quantum Espresso >> Abinit >> Lobster >> ``` >> >> >> [1] https://github.com/romerogroup/pyprocar >> > > In particular, for documentation on spin projections, see here [1]. > > > [1] https://romerogroup.github.io/pyprocar/bands.html#spin-projection > > > Regards, > HZ > > ___ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
[QE-users] How to compute spin projections?
Dear QE users and developers, For non-linear calculations VASP print out on the PROCAR file three othogonal spin projections at each k point of each band. Is there an way to obtain the same information from calculations done in QE? Best regards, Luiz G. D Silveira Associate Professor - UFPR - Brazil ___ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
