Loss of symmetru with Hubbard U |
- Date: 2024/07/18 17:50
- Name: Timon Mosko
<timon.mosko@student.upjs.sk>
- Hello dear experts,
I would like to ask for help regarding the Hubbard calculation. Some time ago I performed calculation of monolayer FeI2 with Hubbard U parameter U=4.8417 eV for Fe d electrons. The effect of this U is shift in several bands in the window around Fermi level which preserves metallicity of the system However I wanted to reproduce my results in some atomic orbital basis code so I chose OpenMX to do so. I have performed calculation without U which is in good agreement with previously obtained results. I use the following basis set:
<Definition.of.Atomic.Species
Fe Fe5.5H-s3p2d2f1 Fe_PBE19H
I I7.0-s3p3d2f1 I_PBE19
Definition.of.Atomic.Species>
When I tried to apply U on the first d orbital d1 (or combination d1 and d2) I observed loss of symmetry in K point. Symmetry of K point is preserved just without U or when I apply it ONLY to d2 orbital. I also observe completly different physical behaviour than is qe, in openmx there is indeed opening of gap at Fermi energy leading to non-metallic state. Could you please provide me with any explanation of this symmetry issue and the difference in metallicity in QE and OpenMX case hubbard calculation case? In both cases I used Dudarev formulation.
I attach bandstructures and OpnemMX inputs.
https://upjs-my.sharepoint.com/:f:/g/personal/5230482_upjs_sk/Esht_9xi8EdAtQTAwZZH6b8BUTazDgukJeyHaLsQjPEB_g?e=OJx8mL
Best regards
Timon M.
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