Questions tagged [dft-u]

Questions related to DFT+U, where U is an extra term involving the Hubbard potential.

Filter by
Sorted by
Tagged with
3 votes
0 answers
91 views

How do we find the starting_ns_eigenvalue for QE calculations?

When performing DFT+U calculation, the ground state might get stuck in a local minimum. In such cases we need to provide starting_ns_eigenvalue to help the ...
Prasad's user avatar
  • 101
4 votes
1 answer
372 views

How to choose the best U value for studying the electronic properties?

I'm new to DFT+U and trying to understand how FeTiO3 works by looking at its electronic properties. But there's a big problem: when I use normal DFT, I can't get the w right band-gap value. How can I ...
Prasad's user avatar
  • 101
2 votes
0 answers
60 views

Temperature effect on electronic properties

I'm particularly interested in studying how temperature affects electronic properties. However, I've been working with Quantum Espresso and its DFT + U functionality, and I'm struggling to understand ...
Prasad's user avatar
  • 101
4 votes
0 answers
79 views

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 ...
Barbaud Julien's user avatar
3 votes
1 answer
211 views

How to set the LMAXMIX tag in VASP for the material BaLaMn2O6?

I am trying to do DFT+U calculation for the material BaLaMn2O6 . As per the vaspwiki it is recommended to set LMAXMIX = 4 (d-elements) and ...
user192399's user avatar
4 votes
0 answers
105 views

Is DFT+U an ab initio based method? [duplicate]

As the title already states is DFT+U considered an ab initio method?
ArD's user avatar
  • 41
5 votes
0 answers
77 views

d-d transitions in materials with transition metals in DFT

While reading the literature on the absorption spectra of materials from the MPX3 group (M= Mn,Ni,Co, Fe; layered antiferromagnets) I come across expressions such as d-d transitions, which are visible ...
M_Fisher's user avatar
  • 631
3 votes
0 answers
225 views

Noncollinear band structure calculation with VASP

I am trying to do a band structure calculation of a noncollinear magnetic system. I am getting results that are nowhere close to what I'm expecting. I need help checking if I am following the right ...
Nani Janelidze's user avatar
6 votes
1 answer
106 views

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?
Jack's user avatar
  • 2,027
4 votes
0 answers
106 views

Hubbard U value on LaAlO3/SrTiO3 interface [closed]

I want to do a GGA+U calculation on the LaAlO3/SrTiO3 heterostructure to study the 2DEG formed at the interface. In all the references I came across they used U around 4eV-6eV on Ti 3d orbitals, I'm ...
ashutosh anand's user avatar
4 votes
1 answer
152 views

Query related to GGA+U calculation in SIESTA

I want to calculate the electronic band structure for CuWO4 using the GGA+U method. Is it necessary to optimize the structure using the same GGA+U method or only we can incorporate GGA+U parameter in ...
Jyotirmoy Deb's user avatar
5 votes
1 answer
102 views

How to plot downfolded bands from DFT bands?

Once you mapped the high symmetry points from primitive cell to the super cell, you need to plot the downfolded bands. As we know in DFT output of band structure calculation we get a set of E vs k ...
Alpha_Roy's user avatar
  • 123
2 votes
1 answer
568 views

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 ...
sAimen94's user avatar
6 votes
0 answers
161 views

DFT+U for RPA Ground State

For RPA calculations in VASP, a four step process can be utilized where the first step is to compute the occupied orbitals at either the GGA or hybrid GGA level. I am curious with materials that are ...
Tristan Maxson's user avatar
8 votes
1 answer
586 views

Do the U values affect structure optimization with the DFT+U simulation to optimize crystal structure?

I am trying to do structure optimization of TiO2, since titanium is a transition metal, I need to use DFT+U to simulate the right band structure, but the electronic band structure would also affect ...
Jack's user avatar
  • 2,027
9 votes
1 answer
248 views

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 ...
Chi Kou's user avatar
  • 5,823
7 votes
1 answer
407 views

How to perform linear response theory calculation of U Hubbard parameter in VASP?

Following to this post, I would like to know how to perform linear response theory for calculation of U Hubbard parameter in VASP?
Chi Kou's user avatar
  • 5,823
6 votes
0 answers
474 views

How to create a CIF using VESTA? [closed]

I am looking into double perovskite materials. One of the possible materials is $\ce{Cs4CuSb2Cl12}$. Now, although there are a few papers which have done ab intio calculations but none of the common ...
Parmeet Singh EP 066's user avatar
8 votes
3 answers
802 views

How to calculate formation energy using DFT+U?

I noticed that a lot of articles use DFT+U methods to calculate different formation energies when using regular DFT and DFT+U methods. For example, in the attached paper[1] on $\ce{In2O3}$, the ...
rmza7's user avatar
  • 329
8 votes
1 answer
1k views

How To calculate formation energy of Ni doped ZnO system in Quantum ESPRESSO?

I have successfully completed the SCF of doped system Ni doped ZnO using GGA+U. I have checked the SCF.out file and found the energy value : E= -6112.0389 Ry. Hwo to calculate the formation energy of ...
ismail benaicha's user avatar
13 votes
0 answers
144 views

Handling multiple self-consistent solutions with DFT+U

It is well-established that within the DFT+U framework, one can achieve several self-consistent solutions with greatly varying energies for the same exact magnetic ordering. In 2010, Meredig et al. ...
Andrew Rosen's user avatar
  • 7,371
7 votes
1 answer
162 views

Will there be a difference between GGA and GGA+$U$ for material with Sc element involved?

I have a material that contains the transition metal element Sc [3$d$1], and I want to know your opinions if there will be a difference between GGA and GGA+$U$ calculation. Knowing that the other ...
Chi Kou's user avatar
  • 5,823
7 votes
3 answers
1k views

How to determine the value of the difference (U-J) in "Dudarev's approach" for GGA+U calculation using the VASP?

I want to conduct GGA+U calculations using Duradev's approach in VASP code on a ...
Chi Kou's user avatar
  • 5,823
6 votes
0 answers
1k views

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 ...
ismail benaicha's user avatar
14 votes
2 answers
953 views

Hubbard U correction for Copper

I am reviewing some information in the Materials Project and notice that they do not use DFT+U to model copper oxides. Since the methodology for fitting U is largely based on the 2006 Ceder paper, I ...
Tristan Maxson's user avatar
11 votes
1 answer
776 views

Charge density convergence within VASP using spin polarized DFT+U

I am noticing a possible convergence problem in a magnetic $U$ system I am studying. In the OSZICAR file I often see the rms(c) value go to about ...
Tristan Maxson's user avatar
16 votes
1 answer
919 views

Are there any good books to learn how to use DFT+U?

I am interested in learning how to do DFT+U calculations and was wondering if anyone has any good recommendations for books or articles.
user139632's user avatar
8 votes
1 answer
404 views

Determine DFT+U values by linear response

I am currently trying to determine how DFT+U values can be determined self consistently. I see that the bare and converged linear response matrix contain the difference in occupancies from the ground ...
Tristan Maxson's user avatar
7 votes
2 answers
662 views

Apply DFT+U to Oxygen/Nitrogen p Orbitals

I often see DFT+U corrections for transition metals with delocalization problems, but a comment about applying a U correction to nitrogen or oxygen's p orbitals also shows up when digging around in ...
Tristan Maxson's user avatar
10 votes
1 answer
83 views

DFT+U Values from Reference Formation Energies

I would like to calculate some DFT+U values for a few elements (Fe, Co, Ni, Cu, Zn?) and am attempting to take the approach from the Ceder 2006 paper. Where does the Ceder paper take its experimental ...
Tristan Maxson's user avatar
22 votes
1 answer
271 views

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 ...
epalos's user avatar
  • 4,789