Questions tagged [quantum-espresso]

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

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23 views

How to generate NEB (Nudget Elastic Band) calculation input file for MoS2? [closed]

I am very new to NEB calculation. I have zero experience to create input file for NEB. If possible Kindly share input file for Monolayer MoS2 and also help how to proceed the calculation.
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41 views

Why extra lines in PDOS plot using xmgrace

Input file for 221 MoS2 &projwfc prefix = 'MoS2', outdir = './out', deltae = 0.1, filproj = 'MoS2-pdos.dat', Another file run ...
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1answer
62 views

What parameters should be checked on both unit cell and super cell to make sure the calculations are going fine?

Question is based on further learning about the previously asked question - Do NSCF calculations on Supercell gives different band gap than the Unit Cell? How should I compare SCF and NSCF ...
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54 views

What input setting in Quantum ESPRESSO will allow me to calculate the free energy of a solid?

I understand that it's possible to calculate the Gibbs free energy of a system ab initio, see for example: How can we calculate the Gibbs free energy from first principles? I'm wondering how I can do ...
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46 views

Cutoff energy in Quantum ESPRESSO calculation [duplicate]

What is cutoff energy in solid state calculations? I would just like a detailed explanation and the applicable formulas!
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83 views

How to obtain spin projected band structure for system with Spin Orbit Coupling?

Spin-orbit coupling[1] means the system has a non-collinear spin. Therefore, spin exists as a spinor, hence there is no meaning to 'up' and 'down' spin. Still, is there any way to get fat-band plot ...
8
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1answer
81 views

Do NSCF calculations on Supercell gives different band gap than the Unit Cell?

NSCF (non-self-consistent field) calculations are done on a dense mesh. I did it on a unit cell. Then since I have to try using a supercell for alloying, I am doing calculations to see the results of ...
6
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1answer
85 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 ...
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1answer
68 views

Tools to Visualize Phonons

Software such as ChemCraft or GaussView is easy to find for vibrational calculations in gas phase, but I am finding it much more difficult to find good visualization software for phonons. I have ...
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42 views

Quantum Espresso error: "SCF correction compared to forces is large: reduce conv_thr to get better values". How to solve?

I'm getting an error when trying to perform a relax calculation for $\ce{H2}$ on $221$ $\ce{MoS2}$. I have tried changing conv_thr and ...
6
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1answer
60 views

What Wyckoff position to put in Input file of Unit Cell of TiCoSb?

$\ce{TiCoSb}$ has Wyckoff position as ...
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1answer
122 views

Spin polarized calculation gives different solution in SIESTA and Quantum ESPRESSO

I was trying to optimize Vanadium doped 4x4 MoS2 using SIESTA. Plotting the band structure I was able to see the symmetry breaking at K and K'. But when I tried to do the same calculation in Quantum ...
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Is it possible to do a collinear spin-orbit calculation in Quantum ESPRESSO?

In the presence of a 2D crystal and spin-orbit coupling, the SU(2) spin axial vector (Sx,Sy,Sz) decouples into an in-plane (Sx,Sy) and out-of-plane part Sz. For Quantum Espresso, is there a way to ...
6
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1answer
48 views

Need INCAR equivalent Quantum Espresso input file

I am dealing with a magnetic system. With Quantum Espresso I am getting the result as a half-metal but while using VASP we are getting it as a semiconductor. I would be glad if someone can provide me ...
7
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1answer
100 views

How do I compile Quantum Espresso with HDF5 support? (Linux)

I've previously installed the Quantum Espresso (QEsp) binaries using "apt install" on an Ubuntu 16.04.7 LTS distro. This has worked fine, except that calculations don't produce .hdf5 output, ...
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1answer
124 views

Physical interpretation of k-points

What is the Physical interpretation of the k-points used in ab initio calculations? Why must the number of k-points be optimized rather than just using some large fixed number of them?
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2answers
88 views

Relation between lattice parameter and energy for relaxations

We have been wanting to do relaxation of lattice parameters as a function of the energy. I want to know the mathematical expression for this, and also the theoretical background related to this method....
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18 views

How to plot berry curvature flux by considering plane in momentum space?

I want to plot the berry curvature flux by considering $k_x$ and $k_y$ plane in momentum space. I have experience running DFT calculations in Quantum ESPRESSO. I have tried reading the user manual of ...
6
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1answer
197 views

Installing Quantum Espresso on an Apple M1 processor possible?

I'm attempting to make QEspresso's pw program on a new 2021 MacBook Air, which has an M1 processor. While ./configure does not throw any errors, running 'make pw' fails with the following output: <...
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36 views

Cutoff length for vdW correction in DFT calculation

In classical MD simulations of lattice structures, whenever we are trying to incorporate vdW corrections to the atomic force calculation, we need to set up cutoff length beyond which the vdW ...
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1answer
67 views

How to confirm whether a system is mott-insulator or not from DFT calculations?

I am using Quantum-Espresso and I need to study mott-insulator. Being a beginner, I am not sure, how do I confirm whether my system is a mott-insulator or not?
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1answer
76 views

In which conditions can the self-consistent Hubbard U value calculated using Quantum Espresso be used for other VASP calculations?

I have seen that some articles calculate Hubbard $U$ value self-consistently using Quantum Espresso code. Then, they use it in VASP calculations. My question is: In which conditions can this value be ...
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1answer
45 views

Case study: KPOINT and band parallelization in Quantum ESPRESSO

I am testing Quantum ESPRESSO with different values for Npool and bands in order to calculate run time. ...
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1answer
51 views

How do I relax only the in-plane component of the unit cell?

I know that &CONTROL='vc-relax' option calculation performs a unit cell relaxation, and that the ATOMIC_POSITIONS can be ...
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1answer
63 views

Quantum Espresso energy cutoff for different pseudopotential

I've been told that I should use the potentials from the Standard Solid-State Pseudopotential (SSSP) library in my simulations. I am interested in $\ce{Pt}$, $\ce{O}$, and $\ce{H}$. Oxygen is ...
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92 views

Case study : Symmetry operation between VASP and Quantum espresso

I am doing simple scf calculation to find similarities in the output of VASP and QE. Recently, I encounter an interesting case. ...
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1answer
94 views

Why am I getting DOS like this in Quantum ESPRESSO?

I am working on $\ce{GeHfTe}$ and in the case of a non-collinear calculation, I am getting the DOS in the attached photo. I have already relaxed my structure with VC-relax and it is converged with ...
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1answer
67 views

Eigen-values not converged, warning in Quantum espresso

I am running a simple example of vc-relax/scf for aluminum using PBE pseudo-potential.Setting are given below ...
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1answer
61 views

How to run hp.x command in Quantum ESPRESSO 6.8?

How to run hp.x command in QuantumEspresso v6.8? It is saying command not found. After doing ...
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1answer
91 views

Simulation of charged species with plane-waves in Quantum Espresso

I am using Quantum Espresso to simulate a platinum surface with ligands, so far everything is working ok. I now need to introduce a solvated hydronium $\ce{H_3O^+(H_2O)_2}$. Is there something I ...
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46 views

How to change the magnetization direction in Quantum ESPRESSO?

I have a magnetic crystal system. I want to calculate the total energy of the system if the magnetization direction is aligned in different directions such as [110], [010]. By default Quantum ESPRESSO ...
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1answer
111 views

Error in nscf calculation while considering Spin Orbit Coupling in Quantum ESPRESSO

I am trying to do the band structure calculation considering the Spin Orbit Coupling but getting the following error: ...
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85 views

How to "Fill the CPU with OpenMP threads" to run QE-GPU

I am trying to run GPU enabled QE (QE 6.8 running on Ubuntu 18.04.5 LTS (GNU/Linux 4.15.0-135-generic x86_64) System Configuration: Processor: Intel Xeon Gold 5120 CPU 2.20 GHz (2 Processor) RAM: 96 ...
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1answer
80 views

Total Energy vs Energy Cut Off convergence

Why is my plot of 'Total Energy vs Energy cut off' is jagged. Previously ecutwfc was kept at 40, 60 and now 80. But still I am unable to figure why isn't it converging. Where as 'Total Energy vs K ...
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570 views

Computational Speed vs multicores

Why is that increasing the number of cores (openMP) in a computation does not decrease the duration of the process? Is it due to consecutive approximation? I took a very simple system of Cu in FCC ...
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1answer
111 views

Command to run QE-GPU

I have installed quantum espresso with GPU support on a system. Ubuntu 18.04.5 LTS (GNU/Linux 4.15.0-135-generic x86_64) System Configuration: Processor: Intel Xeon Gold 5120 CPU 2.20 GHz (2 Processor)...
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60 views

Simple Pt111 slab not converging using Quantum Espresso [closed]

I would like to perform a "vc-relax" calculation on a simple 3x4x5 $\ce{Pt}111$ slab, this calculation is running well but as soon as I add the ESM ...
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44 views

What computational steps needed to characterize the Weyl points?

I am trying to learn the characterization of Weyl nodes computationally. For this, I am using Wannier90 and Z2pack codes in interface with Quantum ESPRESSO. I have done scf, nscf, bands structure, DOS,...
5
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1answer
56 views

Variable Cell Optimization of Halfnium Crystal

Reference: Density Functional Theory: A Practical Introduction, David Sholl, Janice A. Steckel, Chapter 2, Page No. 46 Hf is experimentally observed to be an hcp metal with c/a 1.58. Perform ...
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3answers
116 views

Cu FCC vc-relax method error

Reference: Density Functional Theory: A Practical Introduction, David Sholl, Janice A. Steckel, Chapter 2, Page No. 48 Section 2.2 The fcc Cu calculations in Fig. 2.3 used a cubic supercell with 4 Cu ...
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29 views

DOS projection in alternate axis for eg and t2g contributions

I am studying doping in 0D and 2D perovskites which present tilted octahedra. It is important for me to analyze the contributions in the PDOS in terms of $e_g$ and $t_{2g}$ levels for d orbital in the ...
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27 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": ...
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25 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 ...
7
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1answer
68 views

Calculation of ionization energy for an alloy

How to calculate ionization energy for an alloy system (for eg. $\ce{Mg17Al12}$) using DFT?
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50 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 ...
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1answer
67 views

How to make ferro, feri and antiferro magnetic structure for QE

I have below &SYSTME information from my input file ...
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57 views

Is it possible to calculate non-resonant Raman coefficient in Quantum ESPRESSO 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 ...
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1answer
49 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
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1answer
123 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 ...
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62 views

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 ...