Questions tagged [vasp]

For questions about use of the Vienna Ab initio Simulation Package (VASP).

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9
votes
0answers
198 views

How to build amorphous Al2O3 using the AIMD method implemented in VASP?

I want to build amorphous $\ce{Al_2O_3}$ with the AIMD (ab initio molecular dynamics) method implemented in VASP. I know that two procedures should be taken into account, namely 1st: melt 2nd: quench ...
5
votes
2answers
50 views

How to determine the irreducible representation of an atomic orbital at a K point?

In this paper "Unified theory of direct or indirect band-gap nature of conventional semiconductors", the authors calculated the irreducible representations of atomic orbitals at three K ...
4
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1answer
41 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 ...
5
votes
1answer
43 views

Which one should be investigated first? dynamic stability or magnetic stability?

I would like to investigate the stability of $\ce{VI_3}$ monolayer, but I am confused about whether I start directly by performing Phonon spectrum calculation, or I should first investigate the ...
6
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0answers
82 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
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1answer
111 views

How does electronic iteration work in a VASP relaxation calculation?

I am a beginner using VASP to do material modeling, and I'm confused about the following questions: How does the electronic iteration work in VASP relaxation calculation? Is the electronic iteration ...
6
votes
2answers
80 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....
7
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1answer
99 views

Unit Cell Parameters for VASP Calculations

For background, I have never used VASP before and have limited knowledge of how the software works. I am working on a program for the automation of structural creation for 2D materials. I am more of a ...
8
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1answer
264 views

Study of supercell after creating vacuum

For studying a bulk supercell, after creating some vacuum in it, I'm confused about how to relax it. With VASP, I can do relaxation using NSW = 0 and ...
8
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1answer
76 views

what do I need to change about typical VASP input file to calculate the energy of a single atom?

I'm a little confused how to make a VASP input file to calculate the energy for the isolated atom: Do I need to change the lattice parameter of my unit cell or can keep the value for the whole system?...
6
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0answers
29 views

VASP Memory Estimate

Is there any way to get a memory estimate for VASP calculations either directly or indirectly (based on some example calculation)? For example, I would like to be able to predict based on my settings ...
5
votes
1answer
31 views

How to fix local magnetic moment of each ions in VASP?

In spin-polarized calculation,total magnetic moment can be fixed to a specific value using NUPDOWN tag. In non-colinear spin calculation, tag ...
4
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0answers
31 views

What are the challenges in using DFT to study the Hydrogen Evolution Reaction of (111), (110), (100) and (011) planes of Cobalt (III) Phosphide (CoP)

What are the challenges in using DFT (implemented in the VASP code) to study the hydrogen evolution reaction (HER) of the (111), (110), (100) and (011) surface planes of Cobalt (III) Phosphide CoP
6
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1answer
91 views

How to evaluate the electron relaxation time of nanostructures computationally

I am working with Si nanowires using the SIESTA ab initio code and the BoltzTraP2 Boltzmann transport equation solver. However, the output of the BoltzTraP2 code comes per relaxation time (...
8
votes
1answer
73 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 ...
8
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0answers
43 views

How to choose a proper rotation matrix and apply it to rotate unit cell about Cartesian axis

In this paper, they have rotated the unit cell using a rotation matrix, so the axes are aligned with the atomic bonds. I would like to know how they calculated that rotation matrix, and which software ...
15
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3answers
2k views

How can I use a GUI on a supercomputer?

I am trying to make plots based to VASP simulation results, but I am struggling with how to download so much data from the server. A lot of examples on the internet are taught using the local desktop ...
7
votes
1answer
85 views

Different band gap observed in unitcell and in the supercell

I calculated the bandgap for one system in the unit cell and in the supercell of 2x2x1 and 3x1x1. Although 3x1x1 gives the same bandgap as I got from the unit cell (1.79 eV) but 2x2x1 is giving 1.75 ...
9
votes
1answer
165 views

What is the source of error in this mBJ-LDA calculation?

I am trying to do MBJLDA calculation for bandstructure for WS2 monolayer unit cell using VASP and following the method provided here : Band Structure mBJ-LDA using Vasp, but I am getting an error ...
3
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0answers
48 views

Job stops in between without showing any error

I am trying to calculate the dos of one bulk system. My dos calculation job stops in between without showing any error. Here I am attaching the link of my input dos calculation files. CONTCAR file is ...
10
votes
1answer
93 views

Steps to obtain ionic diffusivity using AIMD

I read a paper and the authors wrote they use AIMD to estimate the ionic diffusivity of materials. I wonder steps to obtain the value at different temperatures. What are the input and output of ...
7
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1answer
82 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
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0answers
49 views

How to efficiently adjust the AMIX_MAG and BMIX_MAG parameter in VASP calculations?

I'm trying to calculate the magnetic anisotropy energy of Cr2O3 by comparing the total energy difference of the system in different spin configurations (in-plane and out-of-plane). However, when ...
7
votes
1answer
98 views

VASP GW PAW Pseudopotentials

What is the difference between the GW and non-GW potentials in VASP. While it is clear that the GW potentials should be used with GW calculations, the documentation also states that these potentials ...
10
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0answers
79 views

Single electron transfer periodic DFT in VASP

I have the following question: I am currently studying the electrocatalytic $\ce{CO2}$ reduction reaction (CO2RR) on $\ce{Cu}$ materials using periodic DFT calculations and I am using the ...
7
votes
0answers
135 views

The gap was open when I was doing an HSE + SOC DFT calculation

I used VASP as my DFT software to do a calculation on an anti-perovskite crystal. I try to reproduce the band structure from literature which was calculated based on HSE + SOC calculation. Their ...
11
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0answers
132 views

Inconsistent data of chemical potential from different papers

I am looking for chemical potential from literature.$^{1,2}$ I compared the method and data they provided. They use the Fitted Elemental Reference Energy method via GGA+U on VASP employing PAW. The U ...
6
votes
1answer
26 views

How to extract information from Charge Density Different?

I would like to learn more about Charge density different and would like suggestion for how to get any information from the Charge Density Different plots. How accurate it is and if anyone have ...
5
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0answers
33 views

What is the minimum supercell size for phonon spectrum calculation for this monolayer system?

Following the previous threads on this topic, I would like to know the minimum supercell size suitable for Phonon spectrum calculation using Phonopy (DFPT) for CrI$_3$ monolayer system given by this ...
10
votes
1answer
138 views

Recommendations to treat 4f electrons (valence) of Yb3+ in magnetic systems in VASP

I need help with: I would like to know what is the most common approach to treat valence 4f electrons of lanthanides (3+ charge) in VASP that circumvents the calculation problems shown below. (or more ...
7
votes
1answer
67 views

How to perform linear response theory calculation of U Hubbard parameter in VASP?

Following to this post, I would like to know how to perform linear response theory for calculation of U Hubbard parameter in VASP?
7
votes
1answer
61 views

How accurate is ALGO= All in VASP?

I was facing convergence problems in my 2D system, but after I have used the ALGO = All tag the convergence problems have gone. I would like to know how accurate is ...
4
votes
1answer
33 views

In VASP, how to perform putting normal stress , with the parameter -PSTRESS?

I found the only parameter related to pressure is Pstress tag in VASP. But the pressure of Pstress tag is Hydrostatic pressure, while I only want to put stress along z-axis. Could you please help me ...
8
votes
1answer
50 views

How is SYMPREC used to determine symmetries compatible with local magnetic moments in VASP?

In DFT calculations using vasp, symmetry analysis are performed to determine space group symmetries at first, if symmetrization is turned on, such as ISYM = 2. When magmoms are set in INCAR, ...
5
votes
1answer
76 views

How to perform carrier-doping in VASP

As my question indicated, I would like to perform carrier (electron-hole) doping. Could you please guide to the right method using VASP ?
6
votes
2answers
87 views

Check the syntax of the VASP input file before running

I am a rookie in the DFT calculation area, I found that I could often make mistakes when writing a new input file, so I'd like to ask if there is a tool for checking the syntax and consistency of ...
13
votes
1answer
184 views

Doubt about energy convergence with different k points

During the convergence test of k points, I observed my energy start increasing instead of decreasing. I am doubtful is this correct or I am doing something wrong. can I take the appropriate K point in ...
4
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0answers
47 views

MedeA VASP: Determination of carrier concentration [duplicate]

My question is, how do I calculate the carrier concentration from a DFT study? I am using MedeA VASP for the DFT simulation.
13
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4answers
831 views

How to make a k-point convergence test for a bulk structure with a lower k-point in the z-direction?

Let's say I want to make k-point convergence test for graphite. And let's say it converges at 12x12x4. Do I first need to do a k-point convergence test for equal k-points on xyz directions then make ...
3
votes
1answer
81 views

Band Structure Calculation with HSE06 Hybrid Functional in VASP

I am using HSE06 hybrid functional to calculate the band structure. I copied IBZKPT file as the KPOINTS file and pasted the k point path for the band structure after this file. The k point path for ...
7
votes
1answer
61 views

Calculation of ionization energy for an alloy

How to calculate ionization energy for an alloy system (for eg. $\ce{Mg17Al12}$) using DFT?
10
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0answers
223 views

Constraining coordination or bond lengths for certain atoms in VASP

I have a structure composed of many MX4 tetrahedral units. When doing MD on this structure I find that just one M atom moves into a trigonal planar coordination (MX3). I was wondering how to set ...
3
votes
1answer
54 views

Determining conduction band minimum of a semiconductor

How can I determine the minimum of the conduction band of a semiconductor using DFT/VASP, or any other option?
10
votes
2answers
185 views

How can I be sure that I have found the conduction band minimum in DFT?

Let's say I want to find the electronic energy bands from DFT calculations in VASP along a chosen path in the Brillouin zone. Now, I want to make sure I choose a path that captures the conduction band ...
3
votes
1answer
124 views

How to do lattice optimization, encut optimization and Kpoint optimization in VASP?

What is the procedure to do lattice optimization, encut optimization and kpoint optimization in VASP? Thank you in advance.
8
votes
1answer
85 views

Phonon frequencies and free energy with respect to polymorphs

I have a material that can crystallize in either a cubic or tetragonal polymorph depending on the synthesis. I used DFPT in VASP and calculated the phonon band structures. I see that the cubic has all ...
6
votes
0answers
139 views

In VASP, which option is better for monolayer relaxation: ISIF=3 or ISIF=4?

Since I have started working on monolayers I was using the ISIF=3 tag for relaxation, this was after recompiling VASP with the modified "...
7
votes
1answer
242 views

HSE06+SOC method using VASP

I have a query on HSE06 + SOC method in VASP. This is a follow-up question to the comment given for a similar question at: How to carry out HSE06+SOC band structure calculation using VASP? I haven't ...
8
votes
1answer
84 views

If Gaussian and Tetrahedron smearing method lead to different Fermi energies, which one is the correct?

In addition to this post, The used settings were : DOS: ISMEAR = -5 SIGMA = 0.2 (default value) BS: ISMEAR = 0 SIGMA = 0.1 Now,...
9
votes
2answers
64 views

Can these Band-gap specifications be attributed to a Half-Semiconductor material?

A Half-Semiconductor is a material with a narrow band-gap for one spin channel and a wide band-gap for the other channel. ...

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