Questions tagged [quantum-espresso]
Questions related to the open source materials modeling framework, Quantum Espresso.
134
questions
3
votes
0answers
6 views
Confused about Effective Screening Medium for surfaces
Using Quantum Espresso I want to perform a slab calculation with a charged ligand ($\ce{H3O+}$), in order to avoid dipole effects across the cell I am using the "Effective Screening Medium":
...
2
votes
0answers
9 views
How to get energy eigenstates using plane wave basis wavefunction .hdf5 output from Quantum ESPRESSO?
When compiled with the HDF5 flag on, Quantum ESPRESSO (QE) saves wavefunctions in the .save folder. At each k-point, we have an $m\times n$ matrix, where $m$ are the complex number entries of ...
4
votes
0answers
19 views
Calculation of ionization energy for an alloy
How to calculate ionization energy for an alloy system (for eg. $\ce{Mg17Al12}$) using DFT?
3
votes
0answers
30 views
How to define ferrimagnetism in quantum Espresso
I would like to pick this problem from my previous post See link.
I am clear about how to define antiferromagnetism in QE.
Here I am with another issue.
I am ...
5
votes
1answer
57 views
How to make ferro, feri and antiferro magnetic structure for QE
I have below &SYSTME information from my input file
...
8
votes
0answers
45 views
Is it possible to calculate non-resonant Raman coefficient for systems that require smearing to converge?
In Quantum espresso turning lraman to true in the ph.x input is not possible if the material is made to converge using smearing. Is there any way to circumvent this, as my material isn't a metallic a ...
8
votes
1answer
42 views
What is the M-point of an orthorhombic crystal structure?
In this paper, they have plotted the band structure of orthorhombic $\ce{CsPbI3}$ using Wein2k. The k-path given here is Γ—X—R—Z—Γ—X—R—A—M—X, but I cannot find the M point in the orthorhombic crystal ...
8
votes
1answer
86 views
Structure visualization software for Windows
I have been using Quantum ESPRESSO for my calculations and I do most of my processing in Linux. Recently I bought a new laptop and it came with Windows and I need to keep it like that for several ...
7
votes
0answers
51 views
Why do I get negative charge density values in the core of atoms when I perform DFT calculations with PAW?
We are all aware of the fact that negative charge densities in the atomic cores are an artefact of Density Functional theory Calculations using Projector Augmented Wave (PAW) method. But what is the ...
4
votes
1answer
71 views
Density functional theory and oxygen spin
I would like to perform single-point/geometry-optimization/NEB calculations on systems involving both molecular oxygens and adsorbed oxygens. Reductions by hydrogens are also involved.
I am still ...
7
votes
0answers
75 views
How to compare the stability of two nano-structures using ab-inito calculations?
I have recently started working on Double Perovskites Quantum Dots and one of the main issue with them is that they are not much stable. Some papers did talk about how much stable there compounds are ...
5
votes
1answer
86 views
How to run multiples VASP files named as POSCAR-XYZ
Is it possible to direct VASP to read a POSCAR-xyz file instead of reading the default POSCAR?
For example, I want to run VASP in the Quantum ESPRESSO format:
...
5
votes
1answer
41 views
What does the "pn" column mean in this pseudopotential file?
In this SSSP pseudopotential file for Quantum ESPRESSO, what does the "pn" column mean?
4
votes
0answers
29 views
How to correct units in the band.yaml file of QE, to band.yaml of VASP
I see from the phonopy web page 1 that the physical unit systems used for the calculators are different for different codes 1. On the same page, it is mentioned that "For these sets of physical ...
13
votes
3answers
1k views
How can I submit jobs to an HPC scheduler?
It is my first time trying to use an HPC system and I am a bit overwhelmed. I have gone through a course on using HPC systems on Coursera and have a basic idea about using Linux. Could you guys tell ...
3
votes
0answers
28 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
37 views
What is the Quantum ESPRESSO equivalent for VASP's k-mesh sampling resolution?
$\require{mediawiki-texvc}$
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 \...
10
votes
1answer
85 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 ...
8
votes
0answers
59 views
Bloch wave function extraction for the specific k-points and specific band from QE calculation [closed]
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 an SCF calculation by QE ...
7
votes
0answers
55 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.
9
votes
1answer
144 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
527 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
97 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
75 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
74 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
30 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
94 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
64 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
101 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
51 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
27 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
186 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
105 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
166 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
114 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 ...
12
votes
1answer
634 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
56 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
179 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
100 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
109 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
189 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
128 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
61 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
55 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
715 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
43 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
522 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
65 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 ...
