Re: [Pw_forum] Pw_forum Digest, Vol 118, Issue 12
Dear Mohammadreza Hosseini, Please try to understand the concept of "back-folding" when using super-cells hen calculating band structures. There are programs to "unfold" the band structure, for example by Jonas Björk. And please do not reply directly to the Digest-messages; use an appropriate Subject and post only the relevant part of the Digest-message - or start a new thread, if there is nothing in the digested message that you refer to, like in your case. Thank you. :) Greetings from the aeroport of Lisbon, apsi -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=- Ari Paavo Seitsonen / ari.p.seitso...@iki.fi / http://www.iki.fi/~apsi/ Ecole Normale Supérieure (ENS), Département de Chimie, Paris Mobile (F) : +33 789 37 24 25(CH) : +41 79 71 90 935 On Sun, 14 May 2017, Mohammadreza Hosseini wrote: Dear All I am calculating the band structure of phagraphyne. First we computed for primitive unit cell and then for the 2X2 supercell. Although the bulk structure is same the band structure is different. What is the problem ? Should parameters be optimized again for supercell? Mohammadreza Hosseini Tarbiat modares uiversity From: pw_forum-boun...@pwscf.org on behalf of pw_forum-requ...@pwscf.org Sent: Saturday, May 13, 2017 10:00 PM To: pw_forum@pwscf.org Subject: Pw_forum Digest, Vol 118, Issue 12 Send Pw_forum mailing list submissions to pw_forum@pwscf.org To subscribe or unsubscribe via the World Wide Web, visit http://pwscf.org/mailman/listinfo/pw_forum or, via email, send a message with subject or body 'help' to pw_forum-requ...@pwscf.org You can reach the person managing the list at pw_forum-ow...@pwscf.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Pw_forum digest..." Today's Topics: 1. Re: how to determine the symmetry of a given phonon mode in quantum espresso (Lorenzo Paulatto) 2. Re: Gipaw - Magnetic susceptibility (Davide Ceresoli) -- Message: 1 Date: Sat, 13 May 2017 15:08:04 +0200 From: Lorenzo Paulatto Subject: Re: [Pw_forum] how to determine the symmetry of a given phonon mode in quantum espresso To: PWSCF Forum Message-ID: <1728518.gkaUiGcZ5e@paulaxps> Content-Type: text/plain; charset="iso-8859-1" On Friday, 12 May 2017 23:44:33 CEST Mihiri Hewa bosthanthirige wrote: Hi, I am graduate student at Clemson university, currently working with Quantum Espresso. I would like to know how to determine the symmetry of a given phonon mode in quantum espresso. Hello, it is printed in the output of phonon at the end of the calculation, i.e.: ... End of self-consistent calculation -- Dr. Lorenzo Paulatto IdR @ IMPMC -- CNRS & Universit? Paris 6 +33 (0)1 44 275 084 / skype: paulatz http://www.impmc.upmc.fr/~paulatto/ 23-24/4?16 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 05 -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20170513/0ddc04ba/attachment-0001.html -- Message: 2 Date: Sat, 13 May 2017 16:09:02 +0200 From: Davide Ceresoli Subject: Re: [Pw_forum] Gipaw - Magnetic susceptibility To: PWSCF Forum Message-ID: <6933968b-d5f1-fb6b-c518-e47ca4ce6...@cnr.it> Content-Type: text/plain; charset=windows-1252; format=flowed Dear Alan, I think that there is no problem in doing a G=0 response with a shifted mesh. The response is at G=0, hence it couples wfcs at the same k. The susceptibility depends a lot on k-points sampling and if your system has a vanishing band gap, convergence can be a nightmare. By default the macroscopic shape is diagonal: nmr_macroscopic_shape(:,:) = 0.d0 nmr_macroscopic_shape(1,1) = 2.d0 / 3.d0 nmr_macroscopic_shape(2,2) = 2.d0 / 3.d0 nmr_macroscopic_shape(3,3) = 2.d0 / 3.d0 You can change the component (demagnetizing field) in the input file. Good luck for your calculations! Best, Davide On 05/12/2017 07:47 PM, Ambrozio wrote: Dear QE users and Developers, I'm working with NMR calculations in Gipaw. Recently I did some shielding calculations and I have some questions regarding the magnetic susceptibility. The article from developers Mauri et al (*PRL 77, 26, 1996*) explain that the shielding of a bulk of a periodic system is also periodic (i.e. has the same periodicity of *G*, the reciprocal lattice vectors), and it is proportional to the magnetic susceptibility matrix. In the paper Mauri did a short discussion about the macroscopic susceptibility, which is calculated at *G=0*. Follow my questions: i) Assuming that the macroscopic susceptibility is calculating at gamma point (*G=0*) and depends of the sample's shape, Does make sense to do a NMR calculation with automatic kpoints (monkhorst pack grid) that does not include the gamma point? It
[Pw_forum] Regarding choosing of pseudo-potentials (PPs)
Dear QE users & Developers I am working on finding properties of doped metal oxides. Currently I am doing relax calculations. I found difficult when choosing of pseudopotentials (PPs) and there I observed three types of PS files: Non-relativistic (NR), scalar-relativistic (SR) and full-relativistic (FR). Can I use mixed type of these PPs in whole relax calculation? OR I have to use same type of PPs in whole relax calculation ? Thanks in advance Regards Phanikumar Research Scholar, Chemical engineering department, IIT Kharagpur, India. ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Pw_forum Digest, Vol 118, Issue 12
Dear All I am calculating the band structure of phagraphyne. First we computed for primitive unit cell and then for the 2X2 supercell. Although the bulk structure is same the band structure is different. What is the problem ? Should parameters be optimized again for supercell? Mohammadreza Hosseini Tarbiat modares uiversity From: pw_forum-boun...@pwscf.org on behalf of pw_forum-requ...@pwscf.org Sent: Saturday, May 13, 2017 10:00 PM To: pw_forum@pwscf.org Subject: Pw_forum Digest, Vol 118, Issue 12 Send Pw_forum mailing list submissions to pw_forum@pwscf.org To subscribe or unsubscribe via the World Wide Web, visit http://pwscf.org/mailman/listinfo/pw_forum or, via email, send a message with subject or body 'help' to pw_forum-requ...@pwscf.org You can reach the person managing the list at pw_forum-ow...@pwscf.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Pw_forum digest..." Today's Topics: 1. Re: how to determine the symmetry of a given phonon mode in quantum espresso (Lorenzo Paulatto) 2. Re: Gipaw - Magnetic susceptibility (Davide Ceresoli) -- Message: 1 Date: Sat, 13 May 2017 15:08:04 +0200 From: Lorenzo Paulatto Subject: Re: [Pw_forum] how to determine the symmetry of a given phonon mode in quantum espresso To: PWSCF Forum Message-ID: <1728518.gkaUiGcZ5e@paulaxps> Content-Type: text/plain; charset="iso-8859-1" On Friday, 12 May 2017 23:44:33 CEST Mihiri Hewa bosthanthirige wrote: > Hi, > I am graduate student at Clemson university, currently working with Quantum > Espresso. I would like to know how to determine the symmetry of a given > phonon mode in quantum espresso. Hello, it is printed in the output of phonon at the end of the calculation, i.e.: ... End of self-consistent calculation -- Dr. Lorenzo Paulatto IdR @ IMPMC -- CNRS & Universit? Paris 6 +33 (0)1 44 275 084 / skype: paulatz http://www.impmc.upmc.fr/~paulatto/ 23-24/4?16 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 05 -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20170513/0ddc04ba/attachment-0001.html -- Message: 2 Date: Sat, 13 May 2017 16:09:02 +0200 From: Davide Ceresoli Subject: Re: [Pw_forum] Gipaw - Magnetic susceptibility To: PWSCF Forum Message-ID: <6933968b-d5f1-fb6b-c518-e47ca4ce6...@cnr.it> Content-Type: text/plain; charset=windows-1252; format=flowed Dear Alan, I think that there is no problem in doing a G=0 response with a shifted mesh. The response is at G=0, hence it couples wfcs at the same k. The susceptibility depends a lot on k-points sampling and if your system has a vanishing band gap, convergence can be a nightmare. By default the macroscopic shape is diagonal: nmr_macroscopic_shape(:,:) = 0.d0 nmr_macroscopic_shape(1,1) = 2.d0 / 3.d0 nmr_macroscopic_shape(2,2) = 2.d0 / 3.d0 nmr_macroscopic_shape(3,3) = 2.d0 / 3.d0 You can change the component (demagnetizing field) in the input file. Good luck for your calculations! Best, Davide On 05/12/2017 07:47 PM, Ambrozio wrote: > Dear QE users and Developers, > > I'm working with NMR calculations in Gipaw. Recently I did some shielding > calculations and I have some questions regarding the magnetic susceptibility. > The article from developers Mauri et al (*PRL 77, 26, 1996*) explain that the > shielding of a bulk of a periodic system is also periodic (i.e. has the same > periodicity of *G*, the reciprocal lattice vectors), and it is proportional to > the magnetic susceptibility matrix. In the paper Mauri did a short discussion > about the macroscopic susceptibility, which is calculated at *G=0*. Follow my > questions: > > i) Assuming that the macroscopic susceptibility is calculating at gamma point > (*G=0*) and depends of the sample's shape, Does make sense to do a NMR > calculation with automatic kpoints (monkhorst pack grid) that does not > include > the gamma point? It is mandatory to including the gamma point when the shape > correction is .true.? > > ii) Does the susceptibility depends of the supercell size? I found very > different susceptibilities for the same material (AB graphite) changing the > supercell size. > > iii) Why the susceptibility matrix is not diagonal when the shape correction > is > .true.? Assuming the Mauri paper I think it doens't make sense. Help me to > understand... > > > I appreciate any help, > > Thanks in advance, > > > Alan. > > > > -- > > Alan J. Romanel Ambrozio > Bacharel em F?sica > Mestre em Eng. de Materiais > Doutorando em F?sica - PPGFis > > > -- +--+ Davide Ceresoli CNR Institute of Molecular Science and Technology (CNR-ISTM) c/o University of Milan, via Golgi 19, 20133 Mi
