# Questions tagged [quantum-espresso]

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

213 questions
Filter by
Sorted by
Tagged with
1 vote
11 views

### quantum espresso ESM calculation

does anyone have experience with calculations involving the ESM method? Effective screening medium. I am trying to study a PbTiO3 slab which is polarized in the z direction and I need to cut the ...
• 191
1 vote
40 views

### 2D charge density contour plot (how to get arbitrary 'Z' values in the plot using python)

I need to generate a contour plot from a file (named abc.gnu) which has X, Y and Z columns of data. It has 1000000 rows of data. I have got the contour plot with a python code (shown at the end). What ...
• 39
38 views

### 3D band structure plot

I am trying to plot 3D band structure of my system of interest. I have used Quantum Espresso software for calculating the band structure and plotted 2D band diagram. But from here I am unable to ...
• 61
19 views

### Free radical based DFT calculations using Quantum Espresso

I wish to explore the possibility of performing free radical based DFT calculations over my Fe(110) slab. I have gone over the internet to see if there is any possibility of carrying this via Quantum ...
• 99
40 views

### Issues converging with DFT+U and magnetism in Quantum ESPRESSO

Dear fellow matter modelers, I am trying to model the zig-zag antiferromagnetic material $\alpha$-RuCl$_3$ using QUANTUM ESPRESSO. My end goal is to include DFT + U + SOC, however, including too many ...
1 vote
47 views

### nspin and starting_magnetization in Quantum Espresso

In Quantum Espresso, there is a parameter called nspin, which I understand to include in INPUT if there is a paramagnetic species, like $\ce{Fe}$. Thus, we also ...
• 99
34 views

### |psi|^2 calculation (1D) for diamond structure silicon not showing full dataset for all bands: Quantum Espresso

Dear Quantum Espresso users, I was trying to calculate the |psi|^2 calculation (1D) for diamond structure silicon at a single kpoint (gamma point). I have used the semicore pseudopotential that ...
• 39
40 views

### Cohesive Energy of a metal oxide

I am trying to calculate the cohesive energy of certain metal oxides. However, I am only able to find a formula that is applicable to systems with a single element (say $\ce{Cu}$ metal or $\ce{Si}$ ...
• 609
19 views

### How to output Berry connection and identify the gauge by changing VASP or QE source code?

Usually, the first-principles packages like VASP and QE involve many aspects to totally figure out what their subroutines do. For example, to output Berry connection $\mathcal{A}^\alpha_{nn}$ used by ...
• 13.9k
34 views

### What occupation should be used for non metallic energetic materials in Quantum espresso?

I am trying to understand the Quantum espresso input file and I intend to do DFT calculation on an Energetic material (TKX-50) consisting of C, H, O, AND N. I have seen that "smearing" ...
39 views

### study of elastic properties under pressure using VASP

I want to replicate this paper, but somehow I cannot get the same results, most important as shown in table 2. Can anyone help me with this? I have attached the INCAR file. If any correction is needed,...
• 489
72 views

### How to construct thin film structure of desired thickness in quantum espresso?

I want to study the properties of thin films using DFT calculation. I have done the bulk crystal calculations in Quantum ESPRESSO but have no idea how can I construct the thin film of desired ...
• 2,361
81 views

### Why is this quantum espresso calculation terminating without any message?

I am new to QE and have been trying to run a QE job on a cluster. When using 3 nodes and 16 ppn, the program runs for a couple of minutes and stops abruptly, giving me an incomplete output file. The ...
1 vote
87 views

### Phonon Dispersion of SrTiO3, EuTiO3 using Quantum Espresso (DFT-U)

the last few days I've tried to calculate the phonon-dispersion of SrTiO3 (STO) and EuTiO3 (ETO) using the PHonon package of QE. SCF, DOS, PDOS and Bandsctructure calculation worked well on these ...
• 21
63 views

### Calculating Elastic constant using thermo_pw: What does frozen_ions mean?

I am trying to calculate elastic constant when strain is applied on a material. Thermo_pw has a command which says in the documentation For each strain, the code relaxes the ions to their equilibrium ...
• 935
130 views

### How to read QE's wfc*.dat files with python

I'm working with QE 7.0 for the computation of some properties of solids. My working theory requires me to access all the information inside the wfc#c.dat/h5 files, created in the prefix.save ...
• 513
63 views

### What does it mean if the Fermi level crosses into the valence band? How about into the conduction band?

Just recently got into DFT and I've been doing a few calculations on my own on Quantum Espresso. I've come up with electronic band structures for materials that I've been looking at and I was hoping ...
• 171
237 views

### Raman Spectra in Quantum Espresso

Does anyone have any experience simulating Raman spectra in Quantum ESPRESSO? Following the example 15 that comes with QE, I have attempted to simulate the Raman spectrum of MgO. I know the lraman ...
• 91
139 views

### Regarding use of GCMC to add water molecules

I am working on a goethite system, and wish to fill the unit cell with water molecules for AIMD simulation using quantum espresso. For this, some papers[1],[2] indicated the use of Grand Canonical ...
• 609
104 views

### Converging geometry of iron slab

I am a sort-of-beginner in Quantum Espresso. I do understand certain terminology in the INPUT file but I am faced with a dilemma. I have been trying to optimize $\ce{Fe}(110)$ system of 100 atoms ...
• 99
99 views

### Scaling and speedup of Real-space based DFT calculations using Finite Elements approach

I have recently encountered paper where the authors have formulated Kohn-Sham equations using the finite-element package deal.II. It stated in paper DFT-FE was significantly faster than QE for all ...
• 3,239
1 vote
25 views

### Convergence of ecutwfc for Sulphur vacant 221MoS2 monolayer

I optimize the ecutwfc for one sulphur vacancy on 221 MoS2 monolayer in Quantum Espresso. From the attached data, which is the correct converged ecutwfc.
• 455
23 views

### How to find the polarity of a surface (such as ZnO 000-1)?

The 0001 and 000-1 surfaces of ZnO are polar, while the other surfaces like 101̅0 and 112̅0 are nonpolar (https://doi.org/10.1021/acs.chemmater.7b01487). What is the difference between polar and non-...
• 609
48 views

### Phonon dispersion calculation error

I am getting the following error error in routine phq_readin (1): reading xq I don't understand what is this error about.
• 935
407 views

### Is it possible for my laptop to get damaged when I perform DFT calculations on Small molecules

A year ago my surface pro's ssd crashed when I ran a optimization job for 40-50 molecules. I am not sure if that is the sole reason or not but the laptop which was working fine for a year or so got ...
• 1,551
1 vote
163 views

### Repeated error in Quantum Espresso "Error in routine potinit (1)"

I have been trying to perform some calculations in Quantum espresso on mono-layer Borophene. Initially, I have optimized the structure which succeeds. Subsequently, I am trying to use this optimized ...
• 69
94 views

### electronic structure of (110) Nb

I need to get the optimal number of layers of (110) niobium that is a good representative of the behavior of the material, but I am facing two problems using Quantum Espresso, I Keep getting the ...
• 151
120 views

### Quantum Espresso calculation for Deuterium

I am a new user of Quantum Espresso. I have to use Deuterium instead of Hydrogen for my work in DFT studies. Hydrogen Pseudopotential file is available in QE website. Please clarify what parameters I ...
• 455
68 views

### How to compute spin projections in QE?

It's well known that VASP can print three orthogonal spin projections at each k point corresponding to each band in the file PROCAR controlled by the tags LORBIT and RWIGS. Is there a way to obtain ...
53 views

### How to find the reduced coordinates of reciprocal lattice vector which defines the kslice plane in first brillouin zone?

I am trying to get the Fermi contour lines of an FCC crystal system. For this, I am trying to use the wannier90 program. I have already done the wannierzation part successfully. Now I am trying to get ...
• 2,361
82 views

### Different band structure in supercell, but not due to band folding

This is my first time asking a question - if I mess something up please let me know and I'll amend. I believe this goes beyond questions on how to use QE so here seems appropriate over the QE forums. ...
• 71
270 views

### How do you approach solving for lattice constants (a, b, and c) for orthorhombic structures using Quantum Espresso?

I'm currently doing some research on perovskite structures and I'm curious about finding out the properties of the orthorhombic lattice. So the cubic structure was easy enough since all sides are the ...
• 171
31 views

### How to select the projections and inner and outer window for wannier90 calculations?

I am new to wannier90 calculations. I am trying to obtain the wannier functions and wannier interpolated band structure. But I am having the problem in setting the parameters like ...
• 2,361
496 views

### Best software to plot Charge densities

I have obtained cube files of charge density difference using Quantum Espresso. I am trying to plot these as a contour plot in an aesthetically pleasing manner with good quality. I'm aware that ...
• 609
204 views

### xcrysden on a macOS Monterey

It seems that Xcrysden is the best software to visualize quantum espresso files. I've followed the directions from Xcrysden and was able to install it on macOS Monterey using MacPorts. However, I ...
• 201
107 views

### Cohesive energy of Cu with Quantum Espresso

Using this input Cu FCC vc-relax method error to calculate Ebulk, I'm trying to calculate the cohesive energy of solid Cu (Ecoh = Eatom − Ebulk). For the Eatom I'm using a similar input but with ' <...
• 201
108 views

### Variable cell relaxation method is not converging in Quantum ESPRESSO

I am trying to optimize the lattice constants 'a' and 'c' for a hexagonal lattice. I am using the PAW pseudopotential here. I have run the SCF calculation with ...
• 2,361
35 views

### Running USPEX with QE in Cluster

I'm using USPEX with Quantum Espresso. I followed the USPEX instruction, and it to works fine initially running all the relaxation calculations for Quantum Espresso input (examples: EX33 and EX36). ...
• 131
100 views

### BoltzTraP script works with which python version?

BoltzTraP code is giving errors in Quantum espresso of indentation and then Typerror: 'Float' object can not be interpreted as an integer. What should I do to run this properly? What should I update ...
• 935
132 views

### How to calculate the d-band from pdos data?

I am trying to find the d-band center of pdos data generated using quantum espresso 6.8. I'm aware that this maybe calculated by the formula:  \frac{\int_{-\infty}^\infty E \cdot \textrm{pdos}(E)dE}{...
• 609
87 views

### How to perform Strain induced properties in Quantum ESPRESSO?

I have to perform strain engineering in a material. The strain would be expansive strain and compressive strain. How do I perform those both? I am currently using the ...
• 935
77 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 ...
• 31
109 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 ...
• 935
158 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 ...
• 3,609
48 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!
• 3,609
243 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 ...
• 1,551
126 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 ...
• 935
273 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 ...
• 935
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 ...