Questions tagged [quantum-espresso]
Questions related to the open source materials modeling framework, Quantum Espresso.
390
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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
5
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0
answers
200
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Electric field in QE calculation [closed]
I want to apply an electric field pointing in z-direction to a two-dimensional crystal residing in the xy-plane using Quantum Espresso. So far I noticed that there are two distinct ways to do so ...
- 297
2
votes
0
answers
50
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Partial atomic charge from lodwin charge - quantum espresso [closed]
Looking to calculate partial atomic charges for a GCMC calculation. I have relaxed a structure with QE. Projwfc.x gives Lodwin charge of a Ni(II) atom as;
...
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6
votes
1
answer
586
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Simulated STM Image with Quantum-ESPRESSO's pp.x
Context: I am an undergraduate "self-taught" noob when it comes to QE. (I've just been using online resources and textbooks thus far.) There are no QE or DFT experts at my university (I have ...
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3
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1
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Why my values of dielectric function don't match litterature (For Yambo with Quantum ESPRESSO)?
I try to reproduce the dielectric function as the picture bellow using Yambo code but the values that I have found in y-axis are so much bigger [-1000,1500] compared to literature. I generated the scf ...
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4
votes
1
answer
110
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How to plot the dielectric function calculated with Yambo?
I want to calculate the optical properties using Yambo.
I used Quantum ESPRESSO 7.0 with Yambo 5.1.0, but I'm facing an issue. When I generate the dielectric function (o.eps_q1_ip) for example the o....
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5
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79
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What is the ibrav value of a rhombohedral structure? [closed]
I have a rhombohedral structure
The SYSTEM and CELL_PARAMETERS blocks looks like this:
&SYSTEM
ibrav = 0
A = 6.058435171
...
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7
votes
3
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310
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Can you calculate Hubbard U parameter for unit cell and then use it value for supercell/slab?
I'm calculating the vacancy formation energy of a 3x3x2 supercell of cerium oxide and need to include a Hubbard parameter for the Ce 4f state. However, computing this parameter separately for the ...
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3
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0
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83
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Quantum Espresso magnetization per site [closed]
Context
I am doing a SCF calculation on Ni-DOBDC (metal-organic framework). I expect the Ni centres to be d8 high spin, so two unpaired electrons. The metal centres are ferromagnetic within a 1D chain ...
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6
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1
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433
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How can I predict the time of a simulation using Quantum ESPRESSO?
I performed a vc-relax calculation with hybrid functional on a 2 atoms material using the command ...
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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/...
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5
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1
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450
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No way to make Quantum Espresso understand variables created by a user inside an input file?
Let's suppose that I prepare an input file, writing certain parameters defining some molecular structure into to run in Quantum Espresso. For simplicity and convenience I have decided to create an ...
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167
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Would it be appropriate to use a Van der Waals-DFT approximation in Quantum ESPRESSO to study the properties of my material (p-type semiconductor)?
I want to study the structural, optical, electronic and transport properties of my material that contains Cu atoms using Quantum ESPRESSO. I tried so many approximations but every time I face an issue ...
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6
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1
answer
523
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How do I install Quantum ESPRESSO on Linux?
People, can someone please help me how to solve this problem with QE 7.0 installation:
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4
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1
answer
516
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What is the difference between relax and multiple scf calculation in Quantum ESPRESSO?
Relaxation calculation gives us the ionic position of the relaxed structure. Now instead of doing a relaxation calculation, if I do fixed point self-consistent field (scf) calculation for varying ...
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1
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572
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Why does my zincblende structure not look cubic?
The structure of my material is zincblende. So normally the structure is cubic. However, when I open the primitive cell with xcrysden it dosen't look 100% cubic. It's a little bit inclined. Also when ...
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3
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0
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46
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Why do I get very intense picks when I use PBE0 with NC PP? [closed]
I used PBE0 to get projected density of states using norm-conserving pseudopotentials with Quantum ESPRESSO. I found very intense picks (scf -> projwfc ) compared to the ones that I found using ...
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2
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0
answers
97
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How to determine high-symmetry points in case of PBE0 using Quantum ESPRESSO? [closed]
Normally when we use PBE-GGA as an approximation we can determine the high symmetry points in x coordinate from the output file of bands.x calculation . But in the ...
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2
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0
answers
90
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DFT calculations [duplicate]
What is the best way to learn DFT (Density Functional Theory) for beginners?
I want to learn DFT (both simulation and theory). I am a beginners in this field. What is the best way to learn it?
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4
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2
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526
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What's the meaning of k-points with weight zero?
In a post from the Quantum Espresso mailing list, a user suggests adding k-points with weight zero to an SCF calculation as a workaround to allow bandstructure to be computed using a hybrid functional....
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5
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1
answer
661
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Extracting band structure data using Boltztrap for Quantum ESPRESSO
I used PBE0 in my calculations using Quantum ESPRESSO . I have ran a scf calculation then I used Boltztrap by running the command btp2 -vv interpolate -m 3 ./ then <...
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4
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1
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187
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How can I transform my unit cell positions to cartesian coordinates?
I have a structure with the parameters bellow:
...
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5
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1
answer
659
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How to model an isolated molecule with Quantum ESPRESSO?
I am trying to model isolated structures such as quantum dots or molecules in Quantum ESPRESSO (QE).
QE uses 3D periodic boundary conditions (PBC) by default. That's why in order to reduce any ...
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3
votes
1
answer
146
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How to add the scissor operator in Quantum ESPRESSO input?
I want to calculate the optical, transport and electronic properties of my material. GGA underestimate the bandgap.
I tried GGA+U but the bandgap is still underestimated and also when I tried to use ...
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4
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0
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171
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Calculation of Carbon Quantum Dots using Quantum ESPRESSO [closed]
I have build a carbon quantum dots model based on this paper. The model looks like this.
I have calculated the density of states of the system, but does not get a desired plot as written on the paper,...
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3
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0
answers
86
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How to calculate the formation energy of a defect using the unit cell? [closed]
I want to dope CuI conventional unit cell using Quantum ESPRESSO.
In previous papers they used different formulas of defect formation energies,and they use supercell. So I'm confused.
What's the ...
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3
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0
answers
27
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Issue with getting pw_bands output file for ws2 [closed]
After running the input pw_bands.in file execution is not stopping even after 10hrs , and the output is not updating anything further after 1 min of the output.
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0
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294
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Quantum ESPRESSO won't work in ASE [closed]
I am trying to use Quantum ESPRESSO in ASE, but I keep getting the following error. When I run pw.x directly from the terminal, it works, so Quantum ESPRESSO ...
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3
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1
answer
145
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How to calculate the lattice parameter of a supercell using Phonopy? (For Quantum ESPRESSO)
I found in the internet a method to generate a supercell from the input file using Phonopy code. And I have a question if someone can clarify my doubts please. The method is as following:
We make an ...
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4
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1
answer
417
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What's the appropriate method to create a supercell for Quantum ESPRESSO?
I created a CIF file using the experimental parameters of my material, then I used it to create my input file for the unit cell using Cif2Cell. After that, I ...
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4
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0
answers
163
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How to calculate spin density in Quantum ESPRESSO? [closed]
I would like to ask how to calculate spin density like shown in Fig 2(f) in this paper using Quantum ESPRESSO? A simple tutorial/example will be appreciated.
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6
votes
1
answer
468
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Why do we not get DOS by summing over all the PDOS?
If we sum over all the PDOS (Projected/Partial Density of States), will we have the total DOS or simply the DOS? This was not the case in my DOS and PDOS results for a simple Al atom. I am wondering ...
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5
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1
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295
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How to calculate lattice parameter?
After 'vc-relax' calculation I got the cell parameters in the picture bellow. I want to mention that my ibrav=1.
I think the optimized lattice parameter in this case is A=11.44879234*1.006676454 .But ...
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7
votes
1
answer
477
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Query on using the exchange-correlation functional GGA or LDA approximation in Quantum ESPRESSO for electronic and magnetic property calculations?
I hope this question finds you well. I am reaching out to seek your advice on using the exchange-correlation functional 'GGA' or 'LDA'approximation calculation in Quantum ESSPRESSO for Calculation of ...
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5
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2
answers
1k
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How to increase the number of CPUs in my computer?
I'm running my calculations using Quantum ESPRESSO on a 10th generation i7 computer (Dell) with Ubuntu.
When I run any calculation using the command ...
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4
votes
0
answers
63
views
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:
...
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0
votes
1
answer
65
views
Ferro and Antiferro magnetic
The number of all the spin up and spin down atoms must be equal in the antiferromagnetic configuration? If I have a structure including 9 atoms what should I do?
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6
votes
1
answer
159
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Confusion regarding specifying a k-point path for phonon dispersions/bandstructure plots
I have been trying to obtain a plot of the phonon dispersion of a BCC metal using Quantum Espresso. In the literature it seems that a commonly reported path is ...
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3
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0
answers
23
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Do I have to repeat my previous calculations after increasing 'diago_david_ndir' in the input file of the bandstructure calculations? [closed]
After doing the convergence test, 'vc-relax' and 'scf' calculations for my material using Quantum ESPRESSO everything went well. But when I wanted to do a 'bands' calculation for bandstructure I got ...
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5
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0
answers
267
views
How to plot the formation energy versus Fermi level? [closed]
I want to dope my material by substitution, and I'm using Quantum Espresso. In previous works I found that they calculate the formation energy then plot a diagrams as the picture bellow. Normally the ...
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2
votes
1
answer
54
views
Are the cell parameters found after doing a 'vc-relax' calculation the ones used to calculate the material properties?
I created a CIF file using the experimental data from literature . After doing a 'vc-relax' calculation do I have to change the lattice parameter, CELL_PARAMETERS and ATOMIC_POSITIONS in my input file,...
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5
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0
answers
223
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Electron-phonon coupling plotted as function of phonon bands [closed]
I'm looking to superimpose electron phonon coupling (EPC) constants per phonon band per k-point as is done in Figures 6c and 6d in this paper, essentially a "fat band" plot where the ...
user4763
3
votes
1
answer
56
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Do I have to use Rwp, RI, Rf and atomic displacement parameter B to create a CIF file?
I want to create the CIF file of CuI using VESTA software.I used the following parameters to create my CIF : space group, lattice parameter, the angles (alpha, beta and gamma), atomic positions of Cu ...
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5
votes
0
answers
111
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Which crystal structure I have to choose for DFT calculations? [closed]
I want to study the properties of NiO as a hole transporting material adapted for perovskite solar cells using Quantum ESPRESSO.
From Materials Project website, I saw that NiO can exist in different ...
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3
votes
1
answer
104
views
How to Model Antiferromagnetic NiO p-type semiconductor?
I'm a beginner in DFT and I want to study the properties of NiO and doped-NiO materials using Quantum ESPRESSO.I found in the internet that I should introduce the spin magnetization in the Input file (...
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3
votes
0
answers
158
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Why is my post-processing calculation using Quantum ESPRESSO not complete after 9 hours? [closed]
I'm working on an i7 laptop with the parallel version of Quantum ESPRESSO (8 processors are running). I ran a post-processing calculation by ...
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1
vote
1
answer
46
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Choose energy cutoff of surface + molecule (Quantum ESPRESSO)
The final system to model is an interface made of 2 surfaces of 12 fcc-Pt atoms each, with a NH3 molecule in between. I'm using ultra-soft pseudopotentials. If I take the energy cutoff (ecutwfc) that ...
2
votes
1
answer
136
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Invalid MIT-MAGIC-COOKIE-1 keyNote when working with mpirun
After installing QUANTUM ESPRESSO on a i7-laptop I tried to do a scf calculation to see if the QUANTUM ESPRESSO works. I got an output, and the results seems to be OK. However, there is an error that ...
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4
votes
1
answer
282
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Why does BURAI give the correct output file but wrong graph?
Edit3: HemanthHaridas' answer explained why BURAI gave me the result. However, when I opened the same output file using XCrySDen, I got a completely different result (the correct one). So, even though ...
- 2,101
2
votes
0
answers
43
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Excited state frequency for periodic systems
Is there any way to calculate the excited state frequencies of a period system using DFT?
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