Questions tagged [quantum-espresso]
Questions related to the open source materials modeling framework, Quantum Espresso.
175
questions
0
votes
0answers
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.
3
votes
0answers
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 ...
6
votes
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 ...
3
votes
0answers
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 ...
3
votes
0answers
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!
8
votes
2answers
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
votes
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
votes
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 ...
10
votes
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 ...
5
votes
0answers
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
votes
1answer
60 views
What Wyckoff position to put in Input file of Unit Cell of TiCoSb?
$\ce{TiCoSb}$ has Wyckoff position as
...
9
votes
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 ...
5
votes
0answers
36 views
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
votes
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
votes
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, ...
13
votes
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?
6
votes
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....
5
votes
0answers
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
votes
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:
<...
5
votes
0answers
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 ...
9
votes
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?
9
votes
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 ...
5
votes
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.
...
6
votes
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 ...
6
votes
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 ...
7
votes
1answer
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. ...
7
votes
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 ...
7
votes
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
...
4
votes
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 ...
9
votes
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 ...
7
votes
0answers
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 ...
10
votes
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:
...
7
votes
0answers
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 ...
6
votes
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 ...
12
votes
2answers
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 ...
10
votes
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)...
3
votes
0answers
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 ...
6
votes
0answers
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
votes
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 ...
8
votes
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 ...
5
votes
0answers
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 ...
7
votes
0answers
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":
...
4
votes
0answers
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
votes
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?
6
votes
0answers
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 ...
5
votes
1answer
67 views
How to make ferro, feri and antiferro magnetic structure for QE
I have below &SYSTME information from my input file
...
9
votes
0answers
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 ...
8
votes
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
votes
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 ...
7
votes
0answers
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 ...