Questions tagged [quantum-espresso]
Questions related to the open source materials modeling framework, Quantum Espresso.
274
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Why do I get negative charge density values in the core of atoms when I perform DFT calculations with PAW? [closed]
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 ...
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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 ...
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How to compare the stability of two nano-structures using ab-inito calculations? [closed]
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 ...
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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:
...
- 93
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What does the "pn" column mean in this pseudopotential file?
In this SSSP pseudopotential file for Quantum ESPRESSO, what does the "pn" column mean?
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How to correct units in the band.yaml file of QE, to band.yaml of VASP [closed]
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 ...
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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 ...
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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 ...
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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 \...
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279
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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 ...
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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 ...
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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.
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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 ...
- 1,015
13
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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 ...
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How to choose K point from this convergence value [closed]
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.
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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.
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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: ...
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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.
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How to run Quantum ESPRESSO on Google Cloud Services or Amazon Web Services [duplicate]
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 ...
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Band Curvature looks like straight lines for (221) MoS2 Monolayer in Quantum ESPRESSO [closed]
In the band structure of (221) $\ce{MoS2}$ supercell, all the curvature are looking like straight lines. I cannot calculate band gap.
...
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Cif2QE (QEtoolkit): Error when using this input file for (221) MoS2 monolayer [closed]
My input file for the (221) $\ce{MoS2}$ monolayer was created through Cif2QE (QEtoolkit):
...
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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 ...
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Simulate plasma-material interactions (PMI) using Density Functional Theory (DFT)? [closed]
I am separately learning about DFT modelling of materials using Quantum ESPRESSO (QE), and the theory of plasma-material interactions (PMI). This made me wonder: Is there any way to model PMI using ...
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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 ...
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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 ...
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573
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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 ...
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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 ...
- 1,641
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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 ...
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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 ...
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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, ...
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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 ...
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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 ...
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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 ...
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329
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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?
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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 ...
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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 ...
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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.
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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 ...
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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...
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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 ...
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178
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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 ...
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Is there a software package to analyse interactions in crystals? [closed]
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 ...
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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 ...
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185
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How to fix gauge in Quantum ESPRESSO? [closed]
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 ...
- 2,131
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439
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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 ...
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301
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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 ...
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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 ...
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437
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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 ...
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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 ...
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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 ...
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