Questions tagged [vasp]
Questions about or related to the Vienna ab-initio Simulation Package (VASP).
28
questions with no upvoted or accepted answers
13
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answers
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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'm thinking of this process in three steps:
Build initial supercell
Melt
Quench
I ...
- 14.6k
8
votes
0
answers
149
views
Different Results obtained while doing multiple runs from same inputs in VASP
I have been trying to optimize the parallelization parameters in VASP. By varying the parameters(such as KPAR and NCORE) I am trying to reduce the Elapsed time that is printed at the end of each line. ...
- 1,641
7
votes
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answers
45
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Which Exchange Correlational Functional should be chosen for calculation of optical properties in VASP using LOPTICS tag?
I am planning on calculating optical properties mainly dielectric constant using LOPTICS tag in VASP. Now for my electronic calculations I have been using HSE06 mainly because of higher accuracy of ...
- 619
6
votes
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71
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Optimizing geometry of materials under pressure using VASP
I am currently trying to reproduce the results of [1], wherein they have pressurized $\ce{Cs_2SnI_6}$ from $0$ to $20$ GPa.
I ran calculations with PBEsol and used the PSTRESS tag in order to optimize ...
- 619
6
votes
0
answers
116
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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 ...
- 10.6k
5
votes
0
answers
172
views
Install pyvasp: how to compile vasp 6.2.0 with hdf5 support
The following makefile.include was supplied to me, which was used for an existing installation of vasp 6.2.0 without hdf5 support. I am trying to modify it to recompile vasp with hdf5 support, in ...
5
votes
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answers
122
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Standard Practice for Relaxation, Band Structure and Density of States Calculations wrt smearing method
My question is mainly one about consistency in the smearing method used for a standard "geometry relaxation + band structure (BS) + density of states (DOS)" set of calculations. This is a ...
- 677
4
votes
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answers
56
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Electron-phonon coupling plotted as function of phonon bands
I'm looking to superimpose electron phonon coupling (EPC) constants per phonon band per k-point as is done in Figures 6c and 6d in this paper, essentially a "fat band" plot where the ...
user4763
4
votes
0
answers
63
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Query about optical absorption spectra
I have one query about data obtained in the optical calculation (absorption coefficient) using GGA. The output came in the format energy xx yy zz xy yz zx for bulk system. I have seen in the ...
- 303
4
votes
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answers
114
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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 ...
3
votes
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answers
70
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VASPKIT usage for Band structure calculation for HSE06 calculation
I was calculating the Band structure for HSE06 Functional using VASPKIT as has been described here. But some seniors of mine told me that this method is not reliable in order to calculate the Band ...
- 619
3
votes
1
answer
79
views
How to carry out Spin-projected band structure calculation( as shown in figure)using VASP?
How to carry out Spin-projected band structure calculation( as shown in figure)using VASP?
I couldn't find any good source for this kind of plotting, is there a code for this kind of plotting other ...
- 547
3
votes
0
answers
77
views
NCORE tag when performing hybrid-functional calculations
Do you set NCORE when performing hybrid-functional calculations?
I heard that NCORE can be set for VASP6, but when I do not set ...
- 353
3
votes
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answers
42
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Why do pseudohydrogen atoms have a charge of 0.75e when calculating GaAs surfaces?
In the literature[1,2], when calculating GaAs or GaN surfaces by DFT (using package VASP), pseudohydrogen atoms with q=0.75e for the dangling bond of As and N, and q=1.25e for the dangling bond of Ga. ...
- 31
3
votes
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answers
78
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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
3
votes
1
answer
177
views
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-...
3
votes
0
answers
223
views
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 ...
- 303
2
votes
0
answers
19
views
Interface area used in the binding energy
I am searching about binding energy calculation for heterostructure and found this article. In the attached refrence artice; Eb = (ECrI3/MoSeTe − ECrI3− EMoSeTe )/S, where ECrI3/MoSeTe, ECrI3, EMoSeTe,...
- 303
2
votes
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answers
48
views
Primitive Translation Vectors from Lattice Vectors (with varying Space Groups)
I am looking at some raw POSCAR data of some Primitive Cells, and I wonder how I can get a simplified directional representation of the lattice vectors. I have two examples:
Example 1:
...
- 1,195
2
votes
0
answers
31
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Excited state frequency for periodic systems
Is there any way to calculate the excited state frequencies of a period system using DFT?
- 21
2
votes
0
answers
62
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Calculating strain field. Need idea on how to do that
Recently I am learning VASP. I am trying to see different properties of two-level system (TLS). For example, checking amorphous silicon as a test case (along with it's vacancy structures as well). ...
- 643
2
votes
0
answers
41
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One query about making the bilayer structure
I want to make one 2d bilayer structure in AB stacking. I made it first in AA stacking. Now I need to figure out how to convert that structure in AB stacking. In literature, I read, "By laterally ...
- 303
2
votes
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answers
70
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How to include the spin-orbit coupling strength of only two or three elements in VASP?
I am trying to calculate magnetic properties in my material with VASP, much like Fig 3b of this paper. The paper says:
"To understand the origin of the SIAin monolayer MnBi2Te4, we performed the ...
- 21
2
votes
0
answers
37
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How to create the supercell to simulate a disordered solid solution?
I am trying to simulate the DOS of a disordered semiconductor (Cd0.5Zn0.5S), my plan is to get the .cif file of CdS first, and build a supercell, then I should ...
- 1,915
2
votes
0
answers
36
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 ...
- 14.6k
1
vote
0
answers
35
views
VASP: HS06 hybrid functional bandstructure with downsampled fock operator
I am using vasp 6.2.0 to calculate bandstructure with HS06 hybrid functional. I have done
a DFT self-consistent calculation with GGA functional, on a uniform 20x20x20 grid; from this I copied the ...
1
vote
0
answers
34
views
Magnetic moment becomes half with SOC
I have one 2d sysytem with 96 atoms in the supercell and I perfromed the relaxation with 551 k-mesh using GGA and I obtined a magnetic moent of 2 mub. For the same system when I performed the ...
- 303
1
vote
0
answers
56
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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 ...
- 1,915