Questions tagged [quantum-espresso]
Questions related to the open source materials modeling framework, Quantum Espresso.
119
questions
3
votes
0answers
16 views
Convert PSP8 pseudopotential files to UPF format
Is there a way to convert psp8 pseudopotential files (used for abinit) to UPF format (used for Quantum ESPRESSO)? I noticed there is the upfconv.x utility in ...
5
votes
1answer
26 views
What is the Quantum ESPRESSO equivalent for VASP's k-mesh sampling resolution?
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Many authors in their research papers involving VASP, report for the k-mesh sampling with a statement like this:
"Gamma-Centered mesh with a resolution of $2\pi \...
6
votes
0answers
36 views
Quantum ESPRESSO ph.x output
I wanted to calculate the normal modes of some particular material using the Quantum ESPRESSO. Everything went fairly well, but there is a couple of lines in the output that I do not understand. In ...
7
votes
0answers
39 views
Bloch wave function extraction for the specific k-points and specific band from QE calculation
I would like to use QE to obtain u_K(r), which is the Bloch wave function of spin-up maximum valance band at K point. If I define the K point in the input file and do a scf calculation by QE including ...
7
votes
0answers
46 views
Calculating lattice thermal conductivity using Quantum ESPRESSO and phonopy
How should I calculate lattice thermal conductivity in Quantum ESPRESSO? I have installed phonopy. My Linux distribution is Ubuntu.
8
votes
1answer
117 views
Quantum espresso vs SIESTA
I want to know which particular calculations are suitable for each of them.
Is SIESTA free, as in can you work on it without license. (question is based on the fact for now that all these will be done ...
12
votes
1answer
503 views
What does occupations='tetrahedra' mean in Quantum ESPRESSO?
I am trying to understand Quantum ESPRESSO input file, line by line. So far everything seems pretty easy to understand. However, I do not know what ...
3
votes
0answers
91 views
How to choose K point from this convergence value
My System is 2H MoS2 unit cell with vacuum. Energy is varied in zig zag form. How can predict the k points from this convergence.
6
votes
1answer
73 views
Which is my correct ecutrho convergence?
For my 221MoS2 supercell, I fixed ecutwfc (60Ry) and k-points (441),
I used ultrasoft pseudopotential for my calculation. Which ecutrho value is correct because all are nearly similar.
6
votes
1answer
61 views
What parameters have to converge before doing a relax calculation?
I am a beginner of Quantum Espresso. I have taken 221 MoS2 Monolayer and done a relax calculation.
In case of bulk system, or any doping in supercell, which is preferred: ...
0
votes
0answers
27 views
In 'relax' calculation output of MoS2 supercell, the following commands displayed [duplicate]
1)iteration # 12 ecut= 60.00 Ry beta= 0.50
CG style diagonalization
c_bands: 1 eigenvalues not converged
c_bands: 1 eigenvalues not converged
c_bands: 5 eigenvalues not converged
ethr = ...
6
votes
1answer
77 views
Converged value of ecutwfc in Quantum Espresso
Which is my ecutwfc converged value in this calculation result.
How to choose ecutrho in quantum espresso calculation.
4
votes
0answers
47 views
How to run Quantum ESPRESSO on Google Cloud Services or Amazon Web Services
As I am exploring material simulations one really hard truth that I have realized is that my gaming laptop is not at all going to cut it for my research work. Currently I am trying to find the ...
6
votes
0answers
98 views
Band Curvature looks like straight lines for (221) MoS2 Monolayer in Quantum ESPRESSO
In the band structure of (221) $\ce{MoS2}$ supercell, all the curvature are looking like straight lines. I cannot calculate band gap.
...
5
votes
0answers
48 views
Cif2QE (QEtoolkit): Error when using this input file for (221) MoS2 monolayer
My input file for the (221) $\ce{MoS2}$ monolayer was created through Cif2QE (QEtoolkit):
...
18
votes
9answers
8k views
How to master Fortran with minimal effort?
Fortran language is used in many first-principles matter modeling codes, such as VASP and QE. These codes usually include many ...
5
votes
0answers
26 views
Is it possible to simulate plasma-material interactions (PMI) using Quantum ESPRESSO? [closed]
I am separately learning about materials modelling using Quantum ESPRESSO (QE), and the theory of plasma-material interactions (PMI). This made me wonder: Is there any way to model PMI using QE even ...
7
votes
1answer
112 views
SCF Calculation not converging after two decimal places in Quantum ESPRESSO
I have been trying to do geometrical optimization for ZnSe Quantum Dots using Quantum ESPRESSO.
The convergence is very slow, so slow that even after 200 iterations I could not get convergence. I ...
13
votes
3answers
5k views
Should I connect 2-3 laptops to form a supercomputer?
I have recently started to use Quantum ESPRESSO for evaluating different properties of ZnSe Quantum Dots. But I currently don't have access to any cluster and as I am increasing the size of ...
8
votes
0answers
78 views
Error while doing a band structure calculation in Quantum ESPRESSO
I have been using BURAI GUI of Quantum ESPRESSO to calculate the optical properties of ZnSe quantum dots. But first I wanted to calculate the electronic band structure. After running the calculation ...
7
votes
1answer
134 views
Running Quantum ESPRESSO on a GPU in Windows
I have been using BURAI GUI for Quantum ESPRESSO for the calculation of optical properties of ZnSe. While running calculations I observed that my laptop's GPU was not even being used and I am a bit ...
11
votes
1answer
108 views
Geometrical Optimization not converging, where am I going wrong?
I am trying to obtain the optical properties of ZnSe Quantum Dots, the problem is that my geometrical optimization is not converging. I used VESTA to create the structure(there is a photo in the ...
11
votes
1answer
619 views
How do we know how much computational power is required for a particular calculation?
So I am super new, although I have gotten the hang of using DFT in Quantum Espresso. I am having a problem with running the calculation for 1.6 nm ZnSe quantum dot. I haven't even gotten to ...
7
votes
0answers
50 views
How to passivate the surface of ZnSe Quantum Dot and apply vacuum to it? [closed]
I have been trying to simulate ZnSe zinc blende quantum dots using Quantum Espresso and its GUI BURAI. But being a beginner I am a little confused about a few things:
How do I passivate the surface, ...
8
votes
1answer
169 views
Why volume of unit cell is not the same as cubing the lattice constant?
I have a cubic-FCC with a=b=c and $\alpha$=$\beta$=$\gamma$=$90^o$. As far as I understand the volume of this cubic unit cell should be a cube of the lattice constant. But this not the case I am ...
7
votes
1answer
99 views
Non-constant Vacuum potential
I relaxed Na2S2 molecule in QuantumEspresso and plotted the planar average of potential energy across z axis so as to find the Vacuum potential. This is the output I got :
As you can see the vacuum ...
8
votes
1answer
79 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 ...
7
votes
1answer
184 views
How to generate Electron Density Fields using DFT?
How may I generate Electron Density Field information using Density Functional Theory calculations? What would my required inputs be like in VASP or Quantum ESPRESSO?
8
votes
1answer
101 views
Can I run an nscf calculation in Quantum ESPRESSO with disk_io='none'?
I had run an SCF calculation on a crystal system in Quantum ESPRESSO and had collected the converged charge density. However, during the NSCF calculation, there is the generation of ...
7
votes
1answer
56 views
Is it possible to install thermo_pw on windows 10?
For research purpose, my team needs to use thermo_pw package for ab-initio simulations. But the issue we are running into is that we cannot find a way to install it on our computer. We are using ...
6
votes
0answers
51 views
Why does the Fermi energy change when doing NSCF at different nbnd values? [closed]
While doing NSCF, I decided to rerun it at higher nbnd values to incorporated more unoccupied states while plotting PDOS. But the Fermi energy gets changed with ...
11
votes
2answers
533 views
What is the difference between DOS and PDOS?
I'm new to DFT. Can you please help me to understand DOS and PDOS (projected density of states) in simple wording? I only want to know some basics of these terms and how they are linked to DFT.
7
votes
1answer
39 views
How to determine the more stable configuration between a flat and a buckled monolayer with DFT?
Using first principles methods (quantum espresso code) I would like to find if a monolayer of a material is flat or buckled. Using the van der Waals interaction in the calculation I found that the ...
8
votes
2answers
442 views
Pressure applied DFT calculations in Quantum ESPRESSO
I am trying to perform the pressure-induced DFT calculations in Quantum ESPRESSO. For this, I have calculated the lattice constant of the cubic structure by vc-relax...
9
votes
1answer
62 views
Are electron dipolar spin-spin interactions included in DFT calculations?
I am studying point defects in hBN using Quantum ESPRESSO. It is not clear if electron spin-spin interactions are typically/can be included in DFT calculations. I understand that spin-orbit ...
6
votes
1answer
42 views
Vibrational frequency analysis for NEB result through Maestro
I have ran a Nudged Elastic Band (NEB) calculation using QuantumEspresso through Maestro to find the potential transition state. Within Maestro there is an option where you can select for NEB type ...
6
votes
0answers
72 views
Is there a software package to analyse interactions in crystals?
I have been using Quantum ESPRESSO, specifically the pp.x module to
study interactions via charge density plots. The process is slow as
for crystals containing ...
10
votes
1answer
71 views
How do I get exact percentage of spin-polarization in Quantum ESPRESSO?
Cross-posted on ResearchGate
I am investigating a near half-metallic / high-spin polarization material. I ran an SCF calculation with nspin = 2, with some starting ...
7
votes
0answers
72 views
How to fix gauge in Quantum Espresso?
I am trying to use Quantum Espresso to manually calculate the Berry phase using the Berry connection, due to evolution along a closed loop in k-space. I want to do this manually instead of using ...
10
votes
1answer
81 views
Can I do a “constrained” geometry optimization in Quantum ESPRESSO, such that certain dopants appear in certain positions even after relaxation?
I am studying the magnetic properties of bulk ZnO, so I am doping it with transition metal elements in order to observe the magnetic spectrum. I replace a Zn atom with a transition metal element at ...
4
votes
1answer
78 views
How can I obtain seperate spin-up and spin-down bands while considering Spin Orbit Coupling in Quantum ESPRESSO?
I have been studying a magnetic material with SoC taken into consideration. The main aim was to obtain the band structure.
when I use spin_component = 1 in the ...
7
votes
1answer
152 views
How to understand the wavefunction outputed by QE with HDF5 format?
Following the answer to my question: What is the best program to manipulate numerical DFT wavefunctions to calculate custom matrix elements?,
I compiled Quantum ESPRESSO with the hdf5 flag on, and now ...
9
votes
2answers
140 views
Can we consider SOC in FM materials using QE?
This is a follow-up question to my question posted here. I've been trying to study the effects of spin-orbit coupling (SOC) on the band structure of ferromagnetic (FM) material VSe$_{2}$. The input ...
11
votes
1answer
46 views
How can I properly attach ligands to a surface?
The main aim of my venture is to study the effect of the presence of surface ions on the band structure of Si slab using Quantum ESPRESSO.
I've tried to use iQmol to attach ligands to the surface. The ...
10
votes
1answer
260 views
How to make sure that my SCF calculation is correct?
hope you are doing well.
I am trying to study the electronic properties of ZnO doped with transition metals (Co, Ni, Fe) using DFT calculation, I am a beginner on DFT calculation using quantum ...
5
votes
0answers
168 views
How to use hp.x in Quantum ESPRESSO to calculate Hubbard parameter
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 ...
8
votes
0answers
80 views
Band structure has unusual lines in the valence band using Quantum ESPRESSO
Currently, I am working on ZnO doped with nickel and cobalt.
I performed the SCF, NCF, BANDS calculation and got the results, the calculation converges without any errors.
After that I used BANDS.X to ...
12
votes
1answer
120 views
What is the best program to manipulate numerical DFT wavefunctions to calculate custom matrix elements?
For pedagogical reasons, I am looking for ways to calculate quantum-mechanical quantities such as $\langle m | \dot{m}\rangle, \langle m | \dot{n}\rangle, \langle m | \ddot{n}\rangle$ using ...
9
votes
1answer
103 views
Should I use a lower threshold for calculations involving SOC?
I'm studying a compound $\ce{VSe_2}$ using the DFT package Quantum ESPRESSO (QE). The following is the input file.
...
4
votes
0answers
30 views
Is there a way I could calculate the pressure and use SOC at the same time?
I have been trying to find the appropriate k-point grid via convergence in quantum ESPRESSO (QE). The following is my input file.
...
