Questions tagged [vasp]
For questions about use of the Vienna Ab initio Simulation Package (VASP).
173
questions
3
votes
0answers
21 views
Can a CHGCAR file be converted into a CIF file?
A .cif file can be used for multiple purposes and is a more generic format to store atomic data.
2
votes
0answers
31 views
How to process electron-density data from a CHGCAR for better handling?
We all know that Vesta helps us visualize the electron clouds present in the CHGCAR data, but I am looking for a better way to process the electron-density data we get in a CHGCAR file for compact ...
5
votes
2answers
56 views
POSCAR data file for a 2D system
I would like to understand how to calculate the band structure of the Graphene monolayer system using DFT. I am using VASP for material simulation. My question is how to write the crystal structure ...
6
votes
2answers
61 views
What is the format of the electron-density data in a CHGCAR file?
Rephrasing the above, what is the pattern in which the electron-density data is stored in the CHGCAR file?
I understand that the electron density data in a CHGCAR file is in the form of a 3D Fortran ...
6
votes
0answers
39 views
How to estimate adsorption energy of Li atom on graphene?
I would like to reproduce the data of adsorption energies published in paper.
For example, they say the adsorption energy for Li atom on graphene is -1.19 eV (estimated by GGA-PBE). I used vasp (5.4) ...
7
votes
1answer
47 views
Benchmark test cases for DFT program or VASP?
Cross-posted on reddit/comp-chem.
I am trying to build my workflow of using DFT to predict properties of some materials, but I am not sure if I do it all right, so I think there might be some ...
11
votes
1answer
71 views
Translating fractional coordinates resulting from conventional cell and primitive cell
I have calculated the band structure of some material where the unit cell was the conventional one (i.e. the lattice vectors are orthogonal). I'm trying now to calculate the same band structure only ...
6
votes
0answers
58 views
How to optimize the geometry of beta PHB in VASP?
I would like to calculate the elastic constants of beta PHB. From this paper. I know that it has P3221 space group. The beta PHB has upward and downward chains, which exist at one lattice site with 50%...
9
votes
1answer
186 views
Increasing k-point grid to take DOS calculation
I was trying to compute some electronic properties for Pd using SIESTA and VASP for some computer practicals in my university, specially focused on band structure and density of states (DOS) using LDA ...
7
votes
1answer
68 views
How to choose a different band path for band structure calculation using VASP?
How can I set a different band path for VASP calculation? For example I want to plot KGMK but not GMKG for graphene?
7
votes
2answers
62 views
Is there a database where one can find the Electron Density data of materials?
The database I am looking for may be experimental, computational or user-generated data. If I end up using the data, I will be providing the necessary citations and credits. Thank You.
7
votes
2answers
52 views
How to take periodic snapshots while running a simulation in VASP?
Same question, rephrased:
What is the procedure to take snapshots at fixed intervals while running an AIMD or DFT Simulation in VASP?
OR
Which parameter in the INCAR file do I modify to achieve ...
8
votes
1answer
99 views
How to create the structure file for these materials?
I want to create a POSCAR or CIF file file for the monolayers with the data mentioned in the table below :
Knowing that the spacegroup is : R-3 (148)
Could you please create the POSCAR/CIF for these ...
4
votes
0answers
41 views
Should I add vdW interaction to estimate chemical potential of metallic elements?
I am considering layered oxides $\ce{LiCoO2}$. Previous papers suggested that vdW interaction should be added to get lattice parameters closer to experimental data. I would like to dope other elements ...
7
votes
1answer
181 views
How to generate Electron Density Fields using DFT?
How may I generate Electron Density Field information using Density Functional Theory calculations? What would my required inputs be like in VASP or Quantum ESPRESSO?
7
votes
2answers
143 views
Why is there a large discrepancy between calculated frequency dependent dielectric function and experimental measurement?
I am calculating the frequency dependent dielectric function of $\ce{SiC}$ using VASP. After a geometry optimization, the INCAR file below is used for the ...
5
votes
0answers
54 views
How to do a Sampling on the boundary of Brillouin zone in VASP
I use VASP to do my DFT calculation. I have to do a self consistent calculation to generate my CHGCAR. I want to ask is there anyway to write the KPOINTS file to generate K-meshing grid which can ...
9
votes
1answer
92 views
Why VASP calculates the elastic constant for another trigonal space group?
Please, help me to understand the problem. I calculated the elastic constants for the beta PHB (Space group P3221 (154)), it has to show the reduced elastic constant matrix (six), however, ...
12
votes
1answer
52 views
What does this temperature & total free energy profile mean (obtained from VASP NVT molecular dynamics simulations)?
In order to obtain molecular dynamics (MD) simulations trajectory for computing phonon dispersion relation at finite temperature, I performed NVT MD simulation using VASP for my target system.
Here is ...
6
votes
1answer
39 views
How to make this DOS plot more smooth and add more points around Fermi level?
I have calculated and plotted the DOS for a doped monolayer 3x3x1 supercell. I want to make the plot more smooth and add more points around Fermi level.
Knowing that these are my settings for the ...
8
votes
1answer
52 views
When import volumetric data (spin density of CHGCAR) to VESTA which option should we pick here?
I am trying to plot SPIN DENSITY isosurfaces using VESTA. I have used vaspkit option 312 to create ...
7
votes
2answers
82 views
How to use gnuplot to draw Bandstructure and DOS from VASP outputs?
I am wondering if you could show me how to use gnuplot to draw bandstructure and DOS plots starting from VASP outputs. If you have any scripts please share them with us.
Thanks.
4
votes
1answer
148 views
How to change the spin-orbit coupling strength in VASP?
Since the effect of spin-orbit coupling plays an important role in a topological insulator, How to change the spin-orbit coupling strength in VASP?
4
votes
1answer
114 views
How to interpret spin density isosurface figures?
The figure below shows the spin density isosurfaces of 3x3x1 ScS2 monolayer supercell doped with Mn atoms. This figure was generated using VASPKIT and ...
6
votes
1answer
45 views
What is the meaning of EATOM tag in the POTCAR files of VASP?
I am wondering what is the meaning of EATOM tag in the POTCAR files of VASP. What is its relationship with the energy of an ...
11
votes
0answers
65 views
Calculation of Gibbs free energy of Mg+ ion using VASP [closed]
I am trying to replicate the $\Delta G_0$ part from this paper.
According to the paper, $\Delta G_0$ is 30% of the difference between atomic energy for per $\ce{Mg}$ atom in the bulk structure and the ...
6
votes
1answer
85 views
What is the best setting for this workstation to speed up VASP calculations?
I am working on HP workstation with :
128 GB of RAM
INTEL(R) XEON E5-2620 V3 with 12 cores
What are the best settings of NCORE, ...
8
votes
1answer
67 views
Calculation of linear coefficient of thermal expansion using VASP-Phonopy for Hexagonal material
We use quasi-harmonic approximation using VASP-Phonopy. In whole calculation we only assume Free energy as function of volume but in case of HCP material which have ...
7
votes
0answers
43 views
Single electron transfer periodic DFT in VASP
I have the following question: I am currently studying the electrocatalytic CO2RR on Cu materials using periodic DFT calculations and I am using the CHE model to describe the proton electron transfer ...
5
votes
1answer
54 views
Divergence behaviour of surface energy
By definition, the surface energy of a thin film or a slab model is defined as
$$
\sigma = \frac{1}{2A}(E_{slab} - N\cdot E_{bulk})
$$
where $N$ is the number of atoms in the thin film and $E_{bulk}$ ...
5
votes
1answer
76 views
How do I extract the wave function from a VASP calculation?
We can obtain a energy band structure of a crystal from a DFT calculation in Vasp. Each point in each band represents an energy eigenvalue with a corresponding wave function from the Schrödinger ...
5
votes
1answer
68 views
Formation energy calculation
I am trying to calculate the formation energy of $\ce{Mg2Si}$ and for the calculation of lowest energy configuration of Bulk $\ce{Si}$: $E(\ce{Si})$ and bulk Mg $E(\ce{Mg})$. I have opted for both ...
8
votes
4answers
2k views
How do I search for a particular string in Linux?
I want to search for a value in the VASP OUTCAR file i.e the format of the line should be
Volume of Typ 1: 98.5 %
What ...
8
votes
2answers
301 views
What is the maximum allowed doping concentration?
Let's consider an example of a 3x3x1 supercell of WS2 monolayer which has 9 W atoms. If we substitute two of them with 2 dopants, the concentration will be 2/9 ...
7
votes
1answer
61 views
How to calculate E_TM in the formation energy formulas?
I found in the literature that the formation energy of doped supercell (e.g.: 4x4x1 supercell with one dopant atom) has many formulas, and the most common one is :
$...
6
votes
1answer
87 views
How to set NCORE, KPAR and NBANDS to speed up calculations on VASP?
I am searching of how to set the tags NCORE, KPAR and NBANDS on a specific systems to speed up calculations. Could you please tell me the rules to follow ?
8
votes
1answer
55 views
How to solve this Bandup software problem?
I have compiled the Bandup software using this command : ./build -compiler gfortran. After that, I tried to follow the tutorial inside the directory ...
5
votes
1answer
44 views
Regarding POSCAR file for bulk Silicon
I am newbie to DFT and I am trying to understand the different input parameters in the VASP POSCAR file of bulk silicon system, provided in the examples here. I am trying to find the lattice constant ...
5
votes
2answers
100 views
What is the RWIGS value for the DOS calculation in VASP?
I want to set the RWIGS value in the INCAR file for the investigation of the density of states (DOS) of $\ce{Mg2Si}$ so what ...
7
votes
1answer
117 views
How to set different exchange correlational functionals in VASP?
I want to test different exchange correlational functional on Magnesium silicide to investigate the electronic properties. For example, if I have the POTCAR library ...
10
votes
1answer
186 views
How to visualize spin density isosurfaces?
What is the package used for visualization of spin density isosurfaces in VASP like the ones shown below? A simple example/tutorial would be very appreciated.
7
votes
1answer
86 views
Band structure calculation
I want to do band structure calculation of Magnesium silicide for GGA in VASP. Can anyone please help how to do this by setting initial ...
7
votes
1answer
68 views
VASP input file for formation energy calculation
I want to calculate the formation energy of $\ce{Mg2Si}$ using VASP. What should be the initial steps to perform this run? What INCAR tags are required? Any help ...
4
votes
0answers
36 views
What are the TS, MBD keywords for new (5.4.+) VASP versions?
I tried IVDW = 2202 for MBD as mentioned on the website but I got the following error:
...
9
votes
1answer
142 views
SCAN-RVV10 geometry optimization
I'm using SCAN-RVV10 to optimize the hexagonal-BN but the optimized geometry doesn't look true as the calculated interlayer distance is far smaller than the experimental value(exp=3.35 Aangstrom, calc=...
8
votes
1answer
53 views
What are the input parameters of VASP for 2D material geometry optimization?
Apparently, my input parameters are not good for geometry relaxation of 2D materials using VASP.
...
6
votes
1answer
120 views
VASP error when trying to do calculations in the presence of an electric field
I am trying to observe the effect of the electric field on 2D materials. I applied electric field by introducing three tags:
...
11
votes
1answer
220 views
Number of KPOINTS in irreducible part of Brillouin zone
I want to investigate the comparison of Total Energy per cell with respect to the number of KPOINTS in the irreducible part of the Brillouin zone but I do not know ...
6
votes
2answers
256 views
How to perform band-structure unfolding in VASP?
I have created a band structure for 3x3x1 doped-supercell using VASP, and I obtained the figure below. Now I want to do band-unfolding. What are the simplest ways ...
8
votes
1answer
267 views
Single point energy calculation in VASP
I want to do single point energy calculations in VASP for $\ce{Mg2Si}$ so what should be initial steps to do? What are tags required in INCAR sufficient to do this ...
