Dear Yin-Ying, > Why is it not recommended or feasible to employ the Hubbard U parameters > right from the first SCF calculation?
It is feasible, you can do that. QE contains just one example with starting U=0.001, but you can use any value. The pmw.x codes reads the Kohn-Sham wavefunctions (which can be DFT or DFT+U), and then builds Wannier functions. Note that these are not maximally localized. In the future releases of QE there will be a possibility to use maximally localized Wannier functions from Wannier90 for DFT+U calculations (we are working on that). HTH Iurii ---------------------------------------------------------- Dr. Iurii TIMROV Tenure-track scientist Laboratory for Materials Simulations (LMS) Paul Scherrer Institut (PSI) CH-5232 Villigen, Switzerland +41 56 310 62 14 https://www.psi.ch/en/lms/people/iurii-timrov ________________________________ From: users <users-boun...@lists.quantum-espresso.org> on behalf of Yin-Ying Ting <y.t...@fz-juelich.de> Sent: Wednesday, January 24, 2024 17:09 To: users@lists.quantum-espresso.org <users@lists.quantum-espresso.org> Subject: [QE-users] Hubbard U Parameters in pmw.x Dear Quantum Espresso Community, I am currently working with the poormanwannier.x (pmw.x) as demonstrated in example05 of PP. In this example, the procedure begins with a self-consistent field (SCF) calculation without the incorporation of Wannier functions (wf) and with very small Hubbard parameters (around 0.001). This is followed by the execution of pmw.x and a subsequent second SCF calculation, this time including Wannier functions and the Hubbard U parameters. My question pertains to the rationale behind this two-step SCF calculation approach, particularly concerning the Hubbard U parameters. Why is it not recommended or feasible to employ the Hubbard U parameters right from the first SCF calculation? Understanding the underlying reasoning for this process would greatly enhance my comprehension of the method and its applications. I appreciate any insights or explanations you can provide. Thank you for your time and assistance. Best regards, PhD student in Forschungszentrum Jülich Yin-Ying Ting -- Forschungszentrum Jülich GmbH Institute of Energy and Climate Research Theory and Computation of Energy Materials (IEK-13) E-mail: y.t...@fz-juelich.de ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ Forschungszentrum Jülich GmbH 52425 Jülich Sitz der Gesellschaft: Jülich Eingetragen im Handelsregister des Amtsgerichts Düren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDir Stefan Müller Geschäftsführung: Prof. Dr. Astrid Lambrecht (Vorsitzende), Karsten Beneke (stellv. Vorsitzender), Dr. Ir. Pieter Jansens ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ _______________________________________________ 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