25
votes
Accepted
What is the appropriate way of determining a value for the Hubbard-like potential U for LDA+U / GGA+U calculations?
This is a bit late, but I would say the short answer to your direct question is: technically no, there is no "standard" reliable way, since there are several approaches to determining U self-...
- 3,081
18
votes
What is the appropriate way of determining a value for the Hubbard-like potential U for LDA+U / GGA+U calculations?
You can calculate U in an ab initio way via linear response theory, for instance. See an example here. However, there is no guarantee that a linear response U value is empirically ideal. That is part ...
- 7,281
17
votes
Accepted
Database or repository with values for the Hubbard potential U?
Unfortunately, I don't believe such a resource exists. One should keep in mind that it's not just a matter of a single U value for every metal, of course. The "best" empirical U value will depend on ...
- 7,281
15
votes
What is the appropriate way of determining a value for the Hubbard-like potential U for LDA+U / GGA+U calculations?
The answer is based on Chapter 1 - The DFT+U: Approaches, Accuracy, and Applications from the book Density Functional Calculations: Recent Progresses of Theory and Application
For practical ...
- 8,922
12
votes
Accepted
The Hund's J - Why can this be quantified?
When I first read your question, I found it somewhat puzzling. I have to admit, I still do in part. Why? Well, even your link defines $J$ as a sum of matrix elements $\langle m,m'|V_{ee}|m',m\rangle$. ...
- 4,711
9
votes
How to calculate the potential in Hubbard-U correction and when to apply it?
I assume you mean including a Hubbard U potential within a Kohn-Sham density functional theory (DFT) calculation. The main reason why you might wish to do this is because you are studying a material ...
- 6,637
8
votes
Accepted
In which conditions can the self-consistent Hubbard U value calculated using Quantum Espresso be used for other VASP calculations?
I have looked into this a bit, I think in general it is ill-advised to mix codes like this unless it is needed, but VASP does not support self-consistent hubbard U (no perturbations at non-zero U). ...
- 10.8k
4
votes
How to run hp.x command in Quantum ESPRESSO 6.8?
Executables are soft-linked in ./bin folder of the parent directory. If you did not compile, please follow these steps.
...
- 663
3
votes
Hubbard model SU(2) symmetry: manifest invariance
The Hubbard Model is already manifestly SU(2) spin-rotation invariant because there are no terms that connect the $\uparrow$ and $\downarrow$ sectors (here by connect, I mean change a $\uparrow$ to a $...
- 6,579
2
votes
Phonon Dispersion of SrTiO3, EuTiO3 using Quantum Espresso (DFT-U)
Follow up: Using a fixed occupation it was possible to get the dielectric constant since then QE won't treat the system as a metal anymore. Since STO is not stable at 0K, ph.x only showed imaginary ...
- 51
2
votes
Is it necessary to use DFT+U when calculating binding energy?
I think the number of $\ce{Ni}$ atoms is too few compared to the organic species, I am afraid the use of an inconsistent $U$ makes the problem more complicated besides the computational cost mentioned ...
- 896
1
vote
could meta-GGA-r2scan descript d electron localization and polaron the same as Hybrid functional?
If I do understand correctly your question, you ask if an exchange correlation functional (r2scan or another functionals in the future) can describe correctly strongly correlated systems.
The answer ...
- 896
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