Questions tagged [hubbard-model]
For questions about (or related to) the Hubbard model.
16
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DFT+U: localizing electrons on combination of atomic orbitals
TLDR: DFT+U is a cheap scheme to help localize electrons on atomic orbitals by penalizing fractional occupancies of such orbitals. However, when one tries to localize an electron/hole on an atomic ...
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Is it necessary to use DFT+U when calculating binding energy?
Recently I am trying to calculate the binding energy between CO2/ C2H2 and MOF (containing Ni, C, H, O, N).
I want to know that do I have to use DFT+U for Ni element in this binding energy calculation?...
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could meta-GGA-r2scan descript d electron localization and polaron the same as Hybrid functional?
I notice that r2scan could be more accurate than rscan, but I am unsure if r2scan could describe the d electron localization without Hubbard+U? Or do I still need Hubbard+U with r2scan?
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Eigenvalues of Hubbard occupancy matrix [closed]
I am studying Hematite (Fe2O3) Antiferromagnetic configuration using QE 7.0 (EDIT: compiled and tried 7.1) at the PBE+U level (U = 4.5).
I obtained an excellent agreement with experimental data on ...
- 61
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What's the meaning of a Hubbard term determined by repeated investigation? [closed]
In the paper bellow they used GGA+U to investigate the structural, electronic and
optical properties of Ag- and Cu-doped ZnO.
https://www.emerald.com/insight/content/doi/10.1108/MI-05-2022-0088/full/...
- 1,957
4
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0
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64
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How to implement Ueff=U−J in a Quantum ESPRESSO input file? [closed]
I want to implement Ueff=U−J in a Quantum ESPRESSO input file, but I don't know how to do that.
I found the following on the internet:
...
- 1,957
2
votes
1
answer
478
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Phonon Dispersion of SrTiO3, EuTiO3 using Quantum Espresso (DFT-U)
the last few days I've tried to calculate the phonon-dispersion of SrTiO3 (STO) and EuTiO3 (ETO) using the PHonon package of QE. SCF, DOS, PDOS and Bandsctructure calculation worked well on these ...
- 51
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172
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The comparison of bandgap value of slab and bulk phase [closed]
I tried to calculate the bandgap of the TiO2-Rutile bulk phase, DFT(not +U) calculation shows the bandgap is about 1.8eV, which is roughly the same as the 1.78eV on the Material Project. When ...
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9
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1
answer
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In which conditions can the self-consistent Hubbard U value calculated using Quantum Espresso be used for other VASP calculations?
I have seen that some articles calculate Hubbard $U$ value self-consistently using Quantum Espresso code. Then, they use it in VASP calculations. My question is: In which conditions can this value be ...
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How to run hp.x command in Quantum ESPRESSO 6.8?
How to run hp.x command in QuantumEspresso v6.8? It is saying command not found.
After doing ...
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4
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1
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Hubbard model SU(2) symmetry: manifest invariance
Could someone explain, is it possible to make Hubbard Hamiltonian manifestly SU(2) invariant? I know about the interaction term, but how would kinetic (hopping effect) term have to look like?
Here I'm ...
- 161
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How to use hp.x in Quantum ESPRESSO to calculate Hubbard parameter [closed]
I want to work with GGA +U on Quantum espresso to calculate the electronic properties of Ni Co co-doped ZnO system, but I can't figure out how to use the hp.x program for my system to calculate the ...
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620
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How to calculate the potential in Hubbard-U correction and when to apply it?
I have seen that in certain cases Hubbard-U correction is relevant yet I have seen a number of papers that have not used it. So, I want to know if there is any theoretical basis for finding this ...
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16
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1
answer
692
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The Hund's J - Why can this be quantified?
I was reading on the implementation of Hubbard 'U' in Density Functional Theory. The Hubbard 'U' can be thought of as a parameter that accounts for the on-site electron-electron interactions in ...
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22
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1
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Database or repository with values for the Hubbard potential U?
The Materials Project and other materials databases have a nice periodic table on their home page that allows you to search for compounds. For some materials, they give an empirical $U$ value used to ...
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What is the appropriate way of determining a value for the Hubbard-like potential U for LDA+U / GGA+U calculations?
It is known that neither LDA or GGA correctly account for the strong on-site Coulomb interaction of localized electrons[1]. A cost-effective way of correcting this is by using a Hubbard-like term $U$. ...
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