Dear Abhirup,
> It seems that turbo_eels does not work with nspin = 2. You are right. As I wrote in my previous email, turbo_eels does not work in the collinear spin-polarised case. However, it works in the noncollinear spin-polarized case, which is activated by setting noncolin=.true. > But it does work without npsin = 2 but with smearing and tot_charge = 0/-1/+1 Right! I.e. this corresponds to the case nspin=1, which is the default. However, personally I never tested turbo_eels for the cases when tot_charge = +1 or -1. Greetings, Iurii -- Dr. Iurii Timrov Postdoctoral Researcher STI - IMX - THEOS and NCCR - MARVEL Swiss Federal Institute of Technology Lausanne (EPFL) CH-1015 Lausanne, Switzerland +41 21 69 34 881 http://people.epfl.ch/265334 ________________________________ From: users <[email protected]> on behalf of Abhirup Patra <[email protected]> Sent: Friday, December 20, 2019 6:32:52 PM To: Quantum ESPRESSO users Forum Subject: Re: [QE-users] k-point algorithm is not tested yet turbo davidson Dear Iurii, Many thanks. It seems that turbo_eels does not work with nspin = 2. It gives an error: Error in routine lr_readin (1): LSDA is not implemented But it does work without npsin = 2 but with smearing and tot_charge = 0/-1/+1 Best, Abhirup ------------------------------------------------------------------------------------------------------------------------------------- Abhirup Patra Postdoctoral Research Fellow Department of Chemistry University of Pennsylvania On Thu, Dec 19, 2019 at 11:49 AM Timrov Iurii <[email protected]<mailto:[email protected]>> wrote: Dear Abhirup, Thank you for clarifications! Please note that the turbo_eels code works for the noncollinear spin-polarization (noncolin=.true.), and including the spin-orbit coupling (if needed). The turbo_eels code works for the general k-points implementation (k=0 is allowed), but it does not work for the "gamma_only" case (i.e. using tricks to speed up calculations). The turbo_lanczos and turbo_davidson codes (which are for the absorption spectroscopy) do not work in the spin-polarized case (both collinear and noncollinear) - yes, you are right. Best, Iurii -- Dr. Iurii Timrov Postdoctoral Researcher STI - IMX - THEOS and NCCR - MARVEL Swiss Federal Institute of Technology Lausanne (EPFL) CH-1015 Lausanne, Switzerland +41 21 69 34 881 http://people.epfl.ch/265334 ________________________________ From: users <[email protected]<mailto:[email protected]>> on behalf of Abhirup Patra <[email protected]<mailto:[email protected]>> Sent: Thursday, December 19, 2019 5:40:47 PM To: Quantum ESPRESSO users Forum Subject: Re: [QE-users] k-point algorithm is not tested yet turbo davidson Dear Iurii, Thanks for the email. Sorry about not explaining it well. Here is what I meant: With spin-polarization and with gamma only kmesh none of the TDDFT code works (i.e. turbo_davidson, turbo_eels, turbo_lanczos). So it is difficult to simulate optical spectra for a "neutral (tot_charge = 0)" doped/defected structure. By "works", I meant that I could run the regular scf-calculation and TDDFT codes for any "non-zero (tot_charge = -1 or +1)" charged structure using "gamma only" kmesh and "non spin-polarization". Please let me know if it's still confusing. Best, Abhirup ------------------------------------------------------------------------------------------------------------------------------------- Abhirup Patra Postdoctoral Research Fellow Department of Chemistry University of Pennsylvania On Thu, Dec 19, 2019 at 4:06 AM Timrov Iurii <[email protected]<mailto:[email protected]>> wrote: Dear Abhirup, Sorry, I miss the point. Could you clarify please what do you mean by saying "it works"? Do you refer to the k-points implementation of the turbo_davidson code or something else? The k-points algorithm must be disabled for all cases (neutral and charged cases), and if this not the case, then I will modify the code in order to disable it. Best, Iurii -- Dr. Iurii Timrov Postdoctoral Researcher STI - IMX - THEOS and NCCR - MARVEL Swiss Federal Institute of Technology Lausanne (EPFL) CH-1015 Lausanne, Switzerland +41 21 69 34 881 http://people.epfl.ch/265334 ________________________________ From: users <[email protected]<mailto:[email protected]>> on behalf of Abhirup Patra <[email protected]<mailto:[email protected]>> Sent: Wednesday, December 18, 2019 9:36:51 PM To: Quantum ESPRESSO users Forum Subject: Re: [QE-users] k-point algorithm is not tested yet turbo davidson Forgot to mention, it only happens if I do not assign any charge to the structure i.e., for neutral case. However, it works for nonzero tot_charge, spin-unpolarized situation with fixed smearing and turb_davidson works fine. Thanks for your comments. Best, Abhirup ------------------------------------------------------------------------------------------------------------------------------------- Abhirup Patra Postdoctoral Research Fellow Department of Chemistry University of Pennsylvania On Wed, Dec 18, 2019 at 3:29 PM Abhirup Patra <[email protected]<mailto:[email protected]>> wrote: Thanks, Iurii. Yes, the spectrum with gamma point is quite reasonable but do not match with the experimental observation. It could be some other issue. However, I am wondering how to do the TDDFT calculation for a doped/defected structure with extra electron or hole. I tried to use turbo_davidson starting from i) scf calculation with npsin= 2 and total magnetization and turbo_davidson does not work since I believe it does not for spin-polarized system, then, I tried ii) scf calculation without any spin-polarization and the scf calculation did not run since it cannot work with an extra charge and 'fixed' occupation, and, finally, iii) scf with smearing but turbo_davidson does not support scf calculation with smearing (ref: https://lists.quantum-espresso.org/pipermail/users/2017-January/037363.html) I believe in this case I cannot use TDDFT of QE to calculate absorption spectra of a defected or doped structure. Am I right here? Best, Abhirup ------------------------------------------------------------------------------------------------------------------------------------- Abhirup Patra Postdoctoral Research Fellow Department of Chemistry University of Pennsylvania On Wed, Dec 18, 2019 at 4:00 AM Timrov Iurii <[email protected]<mailto:[email protected]>> wrote: Dear Abhirup, > However, I am not sure with the number of atoms (~120 or more) GW-BSE > calculations with supercell is actually feasible. Yes, I understand the issue. I do not know if it is feasible. You may try to use e.g. Yambo and see how it goes. Otherwise, since you have already quite a big cell, maybe with k=0 you obtain quite a reasonably converged spectrum (to be checked w.r.t. the cell size) at the TDDFT level in the adiabatic approximation. Regards, Iurii -- Dr. Iurii Timrov Postdoctoral Researcher STI - IMX - THEOS and NCCR - MARVEL Swiss Federal Institute of Technology Lausanne (EPFL) CH-1015 Lausanne, Switzerland +41 21 69 34 881 http://people.epfl.ch/265334 ________________________________ From: users <[email protected]<mailto:[email protected]>> on behalf of Abhirup Patra <[email protected]<mailto:[email protected]>> Sent: Tuesday, December 17, 2019 4:47:01 PM To: Quantum ESPRESSO users Forum Subject: Re: [QE-users] k-point algorithm is not tested yet turbo davidson Thanks very much, Iurii. I really appreciate your answer and it does make sense to me. With gamma point only it works fine. And, you are right, my system is a solid and I am trying to simulate the optical spectrum. However, I am not sure with the number of atoms (~120 or more) GW-BSE calculations with supercell is actually feasible. Best, Abhirup ------------------------------------------------------------------------------------------------------------------------------------- Abhirup Patra Postdoctoral Research Fellow Department of Chemistry University of Pennsylvania On Tue, Dec 17, 2019 at 7:50 AM Timrov Iurii <[email protected]<mailto:[email protected]>> wrote: Dear Abhirup, As you can see from the error message of the turbo_davidson code, the k-points algorithm is not supported. Only Gamma point sampling can be used. If I understand correctly, your system is a solid, right? And you want to use a unit cell with a k-points mesh, right? The turbo_davidson cannot be used in this case. You may try to use a supercell with a Gamma point sampling. But be careful when using TDDFT in the adiabatic approximation for the absorption spectroscopy of solids. I recommend that you check literature on this topic. Maybe you will need to resort to the BSE approach. HTH Iurii Timrov -- Dr. Iurii Timrov Postdoctoral Researcher STI - IMX - THEOS and NCCR - MARVEL Swiss Federal Institute of Technology Lausanne (EPFL) CH-1015 Lausanne, Switzerland +41 21 69 34 881 http://people.epfl.ch/265334 ________________________________ From: users <[email protected]<mailto:[email protected]>> on behalf of Abhirup Patra <[email protected]<mailto:[email protected]>> Sent: Monday, December 16, 2019 6:12:08 PM To: Quantum ESPRESSO users Forum Subject: [QE-users] k-point algorithm is not tested yet turbo davidson Hello, I am trying to use turbo_davidson starting from a SCF calculation using PBE without smearing and spin-polarization. This system is a non-metal with bandgap of 2.6 eV. I gave uniform k-mesh as follows for the bcc structure with lattice constant of 10.34 angstrom. K_POINTS {crystal_b} 9 0.0 0.0 0.0 0 0.0 -0.5 0.0 0 0.0 -0.5 0.5 0 0.5 -0.5 0.5 0 0.5 -0.5 0.0 0 0.5 0.0 0.0 0 0.0 0.0 0.0 0 0.0 0.0 0.5 0 0.5 0.0 0.5 0 &lr_input prefix = 'pristine_pbe' outdir = './' ! wfcdir = './' / &lr_dav num_eign = 35, num_init = 70, num_basis_max = 200, start = 0.0d0 finish = 3.5d0 step = 0.001d0 broadening = 0.005d0 / However, I am getting the following error: Error in routine lr_readin (1): k-point algorithm is not tested yet I am wondering if there is a simple way out to this problem other than explicitly testing different k mesh combinations. Best, Abhirup ------------------------------------------------------------------------------------------------------------------------------------- Abhirup Patra Postdoctoral Research Fellow Department of Chemistry University of Pennsylvania _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso<http://www.max-centre.eu/quantum-espresso>) users mailing list [email protected]<mailto:[email protected]> https://lists.quantum-espresso.org/mailman/listinfo/users _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso<http://www.max-centre.eu/quantum-espresso>) users mailing list [email protected]<mailto:[email protected]> https://lists.quantum-espresso.org/mailman/listinfo/users _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso<http://www.max-centre.eu/quantum-espresso>) users mailing list [email protected]<mailto:[email protected]> https://lists.quantum-espresso.org/mailman/listinfo/users _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso<http://www.max-centre.eu/quantum-espresso>) users mailing list [email protected]<mailto:[email protected]> https://lists.quantum-espresso.org/mailman/listinfo/users
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