Skip to main content

Questions tagged [quantum-espresso]

Questions related to the open source materials modeling framework, Quantum Espresso.

Filter by
Sorted by
Tagged with
2 votes
0 answers
12 views

Issue with hp.x Quantum ESPRESSO Calculation on HPC System

I am trying to run an hp.x Quantum ESPRESSO calculation on an HPC system, but the output is not as expected. The scf calculation runs without any issues. However, ...
7 votes
2 answers
2k views

Meaning of lattice parameters in vc relax calculations

I am performing vc relax calculations to find the effect of pressure on the cell. Both tensile and compression pressure. But I am confused about the lattice ...
4 votes
1 answer
83 views

Average value of lattice parameters from cell trajectory

Is there any post processing tools by which I can get average value of lattice parameters from cell trajectory? For example: I ran 'vc-cp' (CPMD) in quantum espresso (for Silicon) and Si.cel file is ...
2 votes
0 answers
18 views

Supercell Symmetry with VESTA

I have recently generated a Supercell of TiO2 rutile with VESTA. I have started from the CIF file and then I selected the option "search atoms in the new unit cell and add them as new sites" ...
2 votes
0 answers
26 views

Need help about Boltztrap 2

Recently I am calculating thermoelectric properties of a ABX3 perovsktes using Boltztrap2. But I can not understand here how Can I choose the correct k points for scf and nscf calculations. I have use ...
2 votes
0 answers
24 views

Convergence issue of Temperature Dependent Lattice constant using CPMD

I am trying to find out temperature dependent lattice constant (Silicon) using CPMD (NPT-MD). If I want the lattice parameters at 300 K, should I set temp 300 K in both &cell and &ion card? I ...
5 votes
2 answers
63 views

SCF not converging during NEB calculation

During an NEB calculation, the first cycle worked just fine, but my second image would not converge during the second cycle. The total energy and the estimated scf accuracy were converging normally, ...
3 votes
0 answers
15 views

Get the BEEF ensemble energies (both mean and standard deviation) from the Quantuam Espresso output file (pw.pwo)

How do I get the Bayesian Error Estimate Functional with van der Waals correction (BEEF-vdw) ensemble energies (both the point and error estimate) from the Quantum Espresso output file? Thanks for the ...
4 votes
0 answers
26 views

Heterostructure "relax" calculation is taking too much time

I am performing relax for WS2/CrN heterostructure on QE. It has already taken a month and still not converged. I am not sure if ...
3 votes
0 answers
21 views

How to find lattice constant (Si/GaAs/any material) at finite temperature using Car-Parrinello Molecular Dynamics (CPMD)?

Would anyone please guide me stepwise how can I find lattice parameters of a material, for example: Si, GaAs, at a finite temperature using Car-Parrinello Molecular Dynamics (CPMD)? Thank you
2 votes
0 answers
17 views

quantum espresso dipole correction

I am trying to study a two layer structure that contains a ferroelectric layer (PZT) and a second layer that can be an insulator or a metal. I am using a slab configuration with vacuum on each side. ...
6 votes
1 answer
104 views

Which software to model Fermi level position of graphene in an external electric field?

I want to model a graphene layer that is sandwiched in a pn junction under bias (the current flows orthogonal to the graphene layer). According to what I've found in literature graphene can be treated ...
1 vote
0 answers
20 views

How to organize q points in Matdyn.in file (Quantum Espresso)?

To check phonon dispersion of 'Si', I need to prepare matdyn.in file. I have a question regarding the no. of q points (9 in this case), coordinates of q points and no. of q points between a point and ...
5 votes
0 answers
45 views

Error in NEB calculation

I am getting an error when trying to perform an NEB calculation: Error in routine card_atomic_positions (2): two occurrences I tested a simple calculation before ...
4 votes
0 answers
25 views

Can temperature dependent phonon dispersion be solved by EPW package of Quantum Espresso?

Yesterday, I posted a question (How to plot temperature dependent Phonon dispersion using Quantum Espresso?) related to temperature dependency of phonon dispersion. Would it be possible to solve this ...
3 votes
1 answer
124 views

Negative phonon calculation

Hi everyone I'm here again to ask you if you know what I can modify to improve my phonon calculation of rutile I think my issues are rooted in not-so-good cell optimizations, I optimize my starting ...
4 votes
0 answers
30 views

How to plot temperature dependent Phonon dispersion using Quantum Espresso?

Would someone please suggest me how can I plot temperature dependent phonon dispersion using Quantum Espresso? The paper (10.48550/arXiv.2211.15571) plotted phonon dispersion at different temperatures ...
3 votes
0 answers
67 views

Geometry Optimization and Symmetry (Quantum ESPRESSO)

Before asking anything, I'd like to clarify that I'm an almost a beginner in using Quantum ESPRESSO, so my question may be trivial for an advanced user. I'd like to perform a vc-relax calculation on a ...
4 votes
0 answers
27 views

Can I run q2r.x in Gamma point only?

I wanted to try to calculate force constant using q2r.x (for GaAs). To do that I ran pw.x and then ph.x. These packages ran successfully. But when I ran q2r.x, this job is not finished (23 hr, still ...
6 votes
1 answer
264 views

File extension difference of 'charge-density' file created by remote servers and personal computers

Recently, I ran an SCF calculation on a remote server, expecting to run an NSCF calculation afterward. So far, all the SCF calculations I have run on my personal computer have produced a 'charge-...
3 votes
0 answers
64 views

Quantum Espresso - Obtaining Negative Phonon Frequencies

I am new to using Quantum Espresso, I am trying to obtain the phonon dispersion for monolayer InSe. I have previously obtained the band structure with no issues. However, when I move to calculate ...
1 vote
1 answer
32 views

Which occupation and potential should I prefer during the input preparation for Semiconductors (Quantum Espresso)?

I am trying to calculate second order force constants for GaAs (preparing input file for ShengBTE). I successfully ran pw.x, but after that when I ran ph.x, I got the following error. ...
3 votes
0 answers
34 views

How to calculate Zero Point Energy of an adsorbed molecule on a surface with quantum espresso?

I want to calculate zero point energy of a molecule that is adsorbed to a surface (by fixing the surface) with help of quantum espresso? I want a detailed explanation. I am not asking about the modes ...
3 votes
1 answer
43 views

ERROR in NSCF calculation execution in QE

...
1 vote
0 answers
20 views

How to efficiently calculate Hubbard parameters using hp.x for isolated dopant?

Background I know how to use hp.x in case of undoped periodic system. We take a small unit cell, apply some initial guess values to obtain the ground state (pw.x), and then run the hp.x on top of it ...
4 votes
0 answers
33 views

Consequences of starting a new relaxation calculation from the final coordinates of an interrupted run

In order to address oscillating total force during an ongoing relaxation calculation in Quantum ESPRESSO, I've found it effective to interrupt the current run and commence a new relaxation calculation ...
4 votes
0 answers
46 views

Optical properties (temperature dependent dielectric constant) calculation using AIMD/CPMD: Is it possible with Quantum ESPRESSO?

I am trying to find dielectric constant using the mentioned method (10.48550/arXiv.2211.15571). They implement AIMD in VASP. Actually, I am familier with Quantum Espresso (not VASP) and using QE, I ...
4 votes
1 answer
62 views

Why do certain atoms remain fixed during relaxation?

I am running PBE defect calculations on InAs in Quantum Espresso. Whenever I run relax, the first 8 atoms stay fixed in place, while the rest displace by some amount. For example, ...
3 votes
1 answer
54 views

Why is the SCF calculation performed after VC-RELAX more energetically stable than the VC-RELAX calculation in QE

Recently, I performed a vc-relax calculation in QE. After vc-relax, I performed an scf calculation, including all the optimized parameters from the vc-relax output file (cell parameters, atomic ...
4 votes
1 answer
102 views

How to plot absorbance from a Quantum ESPRESSO optical calculation using ε1, ε2, and energy data?

I have a calculation via DFT-RPA, which calculates epsilon_2 and energy (eV). For optical property calculation, we usually plot epsilon_2 vs energy (eV). However, I need to know to convert the y-axis ...
3 votes
1 answer
53 views

Quantum ESPRESSO: how to calculate mobility?

How to calculate the mobility? Could you please share with a simple example (or simpler equation) to do this? Or in other words, if we have $E_g$, $E_F$, $P$, $V_{cell}$, $E_{vb,max}$, $E_{vb,min}$, $\...
13 votes
2 answers
3k views

How to calculate the effective mass from DFT band calculations?

One of the properties used in Solid State Physics, and specially in semiconductor physics, is the effective mass. It can be calculated from the energy dispersion relationship. The simple form, for ...
1 vote
0 answers
35 views

How can i do a variable cell relaxation under the influence of constant field in GPAW?

As a continuation of my previous question, I would like to do variable cell relaxation of BaTiO3 under the influence of a constant electric field. The script I've used is given below: ...
8 votes
1 answer
413 views

Bader charge calculation in Quantum ESPRESSO DFT

I am searching for calculating Bader charge using Quantum ESPRESSO. I am using pseudopotential based DFT calculation. And I have charge density files (cube and XSF formats). My objective is to ...
3 votes
0 answers
46 views

Is there any tool/website available by which I can generate VASP input files?

I am familiar with QE input files, but totally new in VASP. I know by using the quantum espresso input generator(https://www.materialscloud.org/work/tools/qeinputgenerator), we can use CIF file to get ...
5 votes
2 answers
197 views

How to make Quantum espresso input file from Vesta?

here is the CIF file of CaCO3 (http://www.crystallography.net/cod/1010962.html). I have opened it using Vesta and get the following data: ...
6 votes
1 answer
149 views

What's the temperature of the output electronic properties get from Quantum Espresso/VASP, even if we use 298 K cell info (atom position) as an input?

Normally to prepare input file (structure of materials) for Quantum Espresso/VASP, I searched the corresponding CIF file from this website (http://www.crystallography.net/cod/result.php), after that I ...
6 votes
1 answer
47 views

Has anyone used Critic2 with Quantum ESPRESSO? Need help to determine non-nuclear charge determination

I have installed Critic2. Need to know how to determine interstitial site locations of a structure and their charges in those sites (in non nuclear maxima sites). I have calculated 3D charge densities ...
2 votes
0 answers
36 views

Methods of convergence in GW-BSE calculations: Quantum ESPRESSO and BerkleyGW

I have been learning BSE calculation through Quantum ESPRESSO and BerkeleyGW. I have been successful to obtain the silicon optical spectra (via GW-BSE), as instructed in the tutorial. The values of ...
2 votes
0 answers
19 views

Investigation of ferro, ferri, antiferro, para and dia magnetism using QE

Can Quantum ESPRESSO be used to investigate ferromagnetism, ferrimagnetism, antiferromagnetism, diamagnetism, and paramagnetism? If so, could you please elaborate on how these types of magnetism are ...
4 votes
1 answer
58 views

How to get 192 of CeO2 atoms coordinates using Vesta?

Here is the CIF file of CeO2 (http://www.crystallography.net/cod/1562989.html). One of the paper mentioned that they have used 192 CeO2 atoms constructed by 444 primitive cells. To generate the ...
3 votes
0 answers
20 views

Result of FTIR and RAMAN calculations for SiPOCa structure

Using Quantum Espresso models this structure with the following input files. However, the ph.x IR column always shows zero. Does anyone know why this result? ph.x input: ...
7 votes
1 answer
115 views

Does the size of atoms influence the speed of DFT calculations when comparing systems with almost the same number of atoms

How does the size of atoms within a structure influence the speed of DFT (Density Functional Theory) calculations? considering that the calculation speed is known to scale cubically with the number of ...
5 votes
1 answer
222 views

Calculating structural stability of a doped plane

The following image indicates an equation published on a reserach paper which was used to calculate structural stability in a metal atom-substituted graphene sheet. Can anyone tell me if we should ...
7 votes
0 answers
82 views

Correct method for structure optimization using DFT tools

Lets's say I want to start off DFT calculations for a material whose experimental cell constants are known. So I have two ways to get the correct structure to later on calculate, say, band structure ...
2 votes
0 answers
38 views

Stiffness constants C11

How can I accurately extract and reproduce the values of $C_{11}$ for 2D hexagonal structures with two independent in-plane constants $C_{11}$ and $C_{12}$? I've used Vaspkit to extract a value of ...
4 votes
0 answers
35 views

Time efficient way of conducting vc relax calculations while mainting accurate results at the same time

I believe this VC-relaxation calculation will take a significant amount of time to successfully complete. Referring to the literature (which indicates that the vanadium substitution atom is positioned ...
1 vote
0 answers
36 views

Formation and Optimization of Dimers, Trimers, Tetramers, and Beyond

What is the procedure to follow in order to computationally create clusters such as dimers, trimers, or tetramers using Quantum ESPRESSO?
2 votes
1 answer
52 views

Unit cell size for phonon modes

Based on this and some other literature I realize that the number of phonon modes is contingent upon the size of the unit cell. I also understand that in using Quantum ESPRESSO, the study of defects ...
5 votes
1 answer
56 views

Phonon calculations related problems

I am performing phonon calculations ph.x of CsPbBr3 primitive cell in QE v7.2 and it is taking a long time on ...

1
2 3 4 5
11