Questions tagged [vasp]
For questions about use of the Vienna Ab initio Simulation Package (VASP).
320
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Setting MAGMOM in VASP for possible Magnetic configurations
I have been working with a material in which Cu has an unpaired electron due to which the material can exist in various magnetic configurations. I wish to see how various properties change as I switch ...
- 1,471
4
votes
2
answers
63
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VASP structure relaxes to an incorrect ground state
I am using VASP to perform a structural relaxation of $\ce{CuNCN}$. I am using the PAW-PBE POTCAR files for the same and the KPOINTS have been generated using a script. The POSCAR file has been ...
- 235
2
votes
1
answer
49
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How to carry out spin texture calculation( as shown in figure)using VASP?
I could not find any good source for this type of calculation. I'd be very appreciated if someone who is experienced with that to show it step by step
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3
votes
1
answer
116
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DFT-D2 calculations in VASP and Gaussian
We are planning on comparing the results of Quantum dots and Bulk materials for our systems so we are planning to use Gaussian for QD and VASP for Bulk. Considering that we will be comparing their ...
- 1,471
6
votes
1
answer
111
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How to transform the k coordinate into the k path used in the band structure?
When drawing the band structure, I need to transform the coordinate of k-points into a k-path, but I am not sure what the formula is.
I checked the result of siesta,...
- 1,601
3
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0
answers
22
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Anti ferromagnetism of the Entropy Stabilized Oxide (ESO)
I want to do a simple SCF calculation for an entropy stabilised oxide using VASP (DFT code). The chemical formula is (CuCoMgNiZn)O (Rock salt structure) and it is anti-ferromagnetic in nature. I am ...
- 846
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0
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17
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how to choose a basis set when calculating COHP? [closed]
I am trying to use the lobster program to calculate COHP, according to the explanation in the literature, it is better to add unoccupied atom orbitals into the basis set.
The initial step in ...
- 1,601
4
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0
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68
views
Is it possible to build a force field that suits all elements based on vasp's machine learning result?
I have tried to use VASP's machine learning force field calculation during running molecular dynamics simulation with a supercell including some elements of Ti, O, Cu, etc. It does increase the speed ...
- 1,601
3
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42
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Coulomb energy in VASP
In DFT, the Coulomb energy is defined as the sum of Hartree energy, nuclear-electron attraction, and nuclear-nuclear repulsion. In VASP output, we can find the Hartree energy, and also the nuclear-...
2
votes
0
answers
40
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Why does the GPU version of VASP consume a lot of time on STRESS calculation?
I am trying to compare the CPU and GPU versions of VASP.6.3.0, it seems that the GPU version consumes a lot of time on the STRESS item, does it represent the time for calculation stress tensor?
Here ...
- 1,601
2
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30
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How do I find out the subdivisions N_1, N_2 and N_3 in BAND STRUCTURE?
I want to find out how to get subdivisions from vasprun.xml of Brillouin zone. Does anyone know how to do this?
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Getting some errors while extracting the data for phonon band strucutre
I am getting some errors while extracting the data for phonon band structure:
...
7
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0
answers
90
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What is the best cell shape to calculate the energy of a free atom with a periodic DFT code (VASP)?
I want to study the adsorption energies of many different atoms to some surfaces. For that, I need to calculate the energies of free atoms (adsorbates) in a vacuum.
I understand that I am supposed to ...
4
votes
1
answer
89
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Why I have difference between DOS and BAND gap?
As they advise everywhere, SKF should be considered without SOC, and already in NSCF, spin-orbit interaction should be included. But what is the actual question, as I know, band splitting occurs with ...
- 61
8
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4
answers
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DFT code for simulating thousands of atoms in a supercell
I'm trying to simulate a supercell that contains thousands of atoms with the DFT method, but it seems VASP couldn't handle such a large system, its parallel efficiency is relatively low, when I try to ...
- 1,601
6
votes
0
answers
52
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density of state with spin orbit coupling
I have been doing DOS calculations with SOC tag on in VASP, and another calculation without SOC. As shown in the figure the DOS with SOC seems strange! is this wrong? How can I have resolved
I have ...
- 495
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vote
0
answers
28
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how to simulate the size effect with DFT theory?
I am considering simulating the size effect of nanoparticles, the size expands from 0.2nm to 50nm, but when trying to build the model, I am not sure how to reflect the size correctly, for example, if ...
- 1,601
4
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How to save the generated 3d representation of the structure(s) by Viewer3d in Py4vasp?
I used py4vasp to calculate structure from data and then I displayed them in a structure viewer (Viewer3d) by this line: calc.structure[:].plot(). It returns a ...
6
votes
1
answer
469
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How to do simulation when two atoms exist in the same coordinate position in the lattice?
I found that there is a type of substance in which two atoms exist in the same coordinate position in the lattice, for example, FeF3(H2O)3, here is its crystal ...
- 1,601
6
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1
answer
228
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Effective mass of holes was measured using DFT
Effective mass of holes was measured using DFT. The hole value is different for each band, is there a way to get the average or standard value of this value?
It was calculated using the VASP program.
...
- 61
6
votes
1
answer
244
views
Why can't DFT calculate the accurate electronic configuration of the Oxygen atom?
I am trying to do a DFT calculation of Oxygen atoms with the VASP code. My settings follow the official tutorial on the Oxygen atom of VASP. But it turns out the energy levels of the two spin ...
- 1,601
5
votes
0
answers
126
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How to calculate the Gibbs free energy for a reaction?
I am trying to learn how to calculate Gibbs free energy for a reaction. Assuming a reaction for two-dimensional TMDCs:
MoS2 (solid) + 2Se(gas) ---> MoSe2 (solid)+ 2S (gas)
I can calculate the ...
- 1,366
7
votes
0
answers
98
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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 ...
- 3,074
9
votes
2
answers
90
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How to calculate temperature dependent phonon band structure in VASP
I want to calculate phonon band structure using VASP for a double perovskite $\ce{A2BB'X6}$.
Most of the perovskites are well known for dynamical instability at $\pu{0K}$ but show a dynamically stable ...
- 1,633
2
votes
1
answer
98
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NCORE bigger than 1 when performing phonon/vibrational calculation(IBRION=5) in VASP?
When I try to calculate the vibration frequency of TiO2, I set IBRION=5 in VASP, but it turns out I couldn't use NCORE>1 in this situation, once I use NCORE>1, VASP would run for only one ionic ...
- 1,601
4
votes
0
answers
50
views
The ionic step is not convergent when doing DFPT in VASP
I am trying to do DFPT, during the process of moving in different directions, even I set EIDFF=1E-8, the corresponding ionic step is not converged, the relative ...
- 1,601
4
votes
1
answer
104
views
Decide the position of oxygen vacancy via the configuration with the lowest energy?
I am trying to determine the position of oxygen vacancy in $\ce{TiO2}$, is it reasonable to decide it by choosing the configuration with the lowest energy?
It doesn't feel quite right to always choose ...
- 1,601
5
votes
3
answers
123
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Gibbs free energy modification after finishing NEB?
I have finished the NEB calculation, but it seems all the energy I got is Internal energy instead of Gibbs free energy, so do I need to do Gibbs free energy modification? Is there any standard ...
- 1,601
2
votes
1
answer
191
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Reciprocal lattice and k-lattice belong to different groups in VASP
I am trying to do geometry optimization of TiO2 with VASP.
Here is the POSCAR file, which I get from the Materials Project.
...
- 1,601
4
votes
1
answer
203
views
Why does the temperature fluctuate severely during the AIMD using an NVT ensemble?
I am trying to raise the temperature of my model and keep the temperature at 300K, with an NVT ensemble and Nose-Hoover thermostat.
I am doing this job with VASP, here is the ...
- 1,601
2
votes
0
answers
74
views
Rashba effect and VASP
How to prove by first-principles DFT calculations that the compound has Strong spin-orbit coupling and Rashba effect
- 495
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0
answers
73
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Problem while performing the BSE GW calculations in VASP
I am trying to learn the BSE GW calculations in VASP. Using the procedure described on the VASP website.
I am stuck at the last step 5 (BSE calculation). I didn't get any error in the 5th step but ...
3
votes
0
answers
71
views
band structure and primitive cell
When I use VASPKIT tool or SeeK-path to generate K-path file for a band structure calculation, it gives a PRIMCELL.vasp file , which has a unit cell that is ...
- 495
4
votes
1
answer
74
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Elastic constant calculation
I want to calculate elastic constants with VASP "by hand" (not by, e.g., DFPT) as I have a big structure (64 atoms). For this, I am making tests on $\ce{Si}$ at the moment.
So, I have done ...
- 91
5
votes
0
answers
29
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"Failed" running DDEC6 Atomic Charge when using Palladium (Pd) cluster model
I have a problem with running DDEC6 when I used Palladium (Pd) cluster, the main issue was that there were no DDEC6_even_templered_net_atomic_charges.xyz files came ...
- 51
5
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answers
47
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Optical Property calculation in VASP using HSE [closed]
I have calculated frequency-dependent dielectric constant in VASP using PBE exchange-correlation functional, within the framework of Independent particle approximation (with RPA). I want to perform ...
- 51
6
votes
1
answer
111
views
How to calculate the magnetic anisotropy energy using the VASP code?
I want to calculate the magnetic anisotropy energy of the CrI$_3$ monolayer which has 8 atoms per unit cell. I have understood from VASPWIKI that there are two steps:
A standard SCF collinear ...
- 5,501
4
votes
0
answers
76
views
RPA calculations with Hybrid Functionals
When doing RPA calculations as explained here, if I want to calculate it with hybrid PBE0 should I put LHFCALC = .TRUE. for just step 1 or step 1, step 3 and step 4?...
4
votes
1
answer
112
views
What are the precise forms for the SU(2) and rotation matrices in VASP?
Some time ago, I conducted a discussion with Dr. Gui-Bin Liu on topological materials here. One relevant thing he said was:
"The format of trace.txt file is only a necessary condition to be used ...
- 83
5
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0
answers
72
views
How to calculate spontaneous polarization of system in VASP
Can anyone describe standard procedure for calculating polarization in VASP. Usually polarization calculation is done on unit cell in VASP or any other codes. For my system with partial occupancies i ...
- 91
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votes
0
answers
91
views
Evaluating Absorption coefficient using VASPKIT for nanostructures
I was planning to use VASPKIT in order to determine the Linear optical properties of my nanostructure. But upon running vaspkit, I do not see an option for 0D materials but only for 2D and Bulk.
Is ...
- 1,471
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votes
0
answers
73
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Minimum number of kpoints for calculation of properties of nanoparticles in vasp
I am a little confused about what should be the correct number of kpoints that I wanna use. I am currently working on a small cluster so picking a high value(even around 10) gives me a memory fault. ...
- 1,471
7
votes
1
answer
111
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The relationship between average eigenvalue and convergence performance in VASP?
I meet some convergence problems when doing self-consistent field calculation in VASP, I find some parameters on VASP wiki that might be able to tune the convergence performance. But I don't quite ...
- 1,601
6
votes
1
answer
263
views
Reorder the atoms in the POSCAR file
I want to rearrange the order of the atoms in the POSCAR file, is there any software able to do this? For example, in the below POSCAR file, I want to put Ti atoms before others.
...
- 1,601
6
votes
1
answer
100
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Which atoms should be fixed when simulating metal oxides surface relaxation?
I am trying to model the surface relaxation on the TiO2(Anatase-101) surface, but it confuses me that when I try to set some atoms as fixed, unlike the crystal that only contains one element, there is ...
- 1,601
4
votes
0
answers
137
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VASP error in berry phase calculation, system is not insulated
I am trying to calculate polarization for a system. Vasp is skipping the LCALCPOL tag calculation because the system is not insulated. How can I make the system ...
- 91
6
votes
3
answers
483
views
Unable to install P4Vasp
I am currently learning how to use VASP and was looking at how to get the DOS plots. I have been recommended to use P4VASP but due to some reason I am not able to install it on my Ubuntu 20.04. When I ...
- 1,471
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can anyone please explain what is meaning of band.conf , mesh.conf and pdos.conf in phonon calculation?
Can anyone please explain, what is the physical meaning of band.conf, mesh.conf and pdos.conf in phonon calculation?
if it is possible please explain about tags used in it.
- 429
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61
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DFT+U for RPA Ground State
For RPA calculations in VASP, a four step process can be utilized where the first step is to compute the occupied orbitals at either the GGA or hybrid GGA level.
I am curious with materials that are ...
- 9,906
9
votes
2
answers
304
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How is the right k-path chosen for band structure?
When generating the kpoint by vaspkit for two compounds that have the same lattice system, I found the kpath is
G–X–S–Y–G–Z–U–R–T–Z|Y–T|U–X|S–R.
But why in the article (as shown in the picture) was a ...
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