Questions tagged [band-structure]

Questions about the band structure of solids. Band theory forms the foundation of the understanding of all solid-state devices.

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11
votes
1answer
67 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 ...
4
votes
1answer
47 views

VASP GW+SOC band structure calculations

How may I carry out GW+SOC a band structure calculation using VASP? Could anyone familiar describe it step-by-step? I could not find any info regarding this on the VASP wiki.
9
votes
1answer
142 views

What is the electrical behavior of the material with this band gap?

Presently I am doing DFT calculations to analyse the electronic structure of a material. I got the band structure as shown in the figure. I would like to know the electrical behavior of this material. ...
16
votes
1answer
266 views

How to separate the data plot for spin up and spin down band structure into 2 different graphs, in Pymatgen?

I am a beginner user of the Pymatgen package. In order to process the data from VASP DFT calculation software, I use Pymatgen to visualize the output band structure. When I do spin polarised band ...
7
votes
1answer
67 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?
10
votes
3answers
255 views

How to create a 3D band structure from DFT band structure calculation?

How can I create such a 3D plot using matplotlib? Like the one in Figure (a) below: I want to create it using DFT bandstructure calculation result
7
votes
0answers
49 views

What are some types of topologically-relevant band degeneracies in contemporary 2D condensed matter research?

Cross-posted the question here: https://physics.stackexchange.com/q/633457/49107 In the study of 2D condensed matter systems, I have seen several kinds of band degeneracies. I call 'bands' the ...
7
votes
0answers
44 views

Band unfolding for magnetic systems

I'm trying to study the electronic structure of a 1D antiferromagnetic (in which the spin is associated with copper atoms) via spin-polarized calculations. The unit cell dimensions are provided below (...
9
votes
1answer
204 views

How to calculate the band structure of a protein molecule

I want to calculate the band structure of a protein molecule. How can I do it using Siesta of Gaussian? I am thinking about QE/VASP as the number of atoms are 600 and computationally it is not ...
5
votes
0answers
36 views

Construct a parity operator in TRIM

I want to calculate the band parity at some TRIM in Brillouin zone. Parity was defined as the eigenvalue of the inversion operator. My question is how to construct the matrix representation of the ...
7
votes
0answers
98 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 ...
7
votes
0answers
39 views

Is it possible to construct a tight binding matrix of high atomic layer thin film from the lower one?

Give a tight binding matrix of a few atomic layer thin film system, is it possible to construct a tight binding matrix of higher atomic layers thin film from the lower one? For example, I have a 4 ...
13
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2answers
106 views

Rashba effect in 2D systems

Can someone explain how to verify the presence of Rashba effect from the band structure calculations?
16
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1answer
1k views

How to understand the time-reversal symmetry in graphene?

A lot of references say that the Dirac cone in graphene is protected by inversion and time-reversal symmetries. How can one understand this statement? How can one show explicitly that the gapless ...
9
votes
2answers
245 views

How to make a good HSE06 bandstructure for TMDC monolayer material (e.g.: WS2) in terms of VASP calculation INPUTS?

I want to perform HSE06 band-structure calculation of a WS2 monolayerwhich has the following POSCAR with ...
12
votes
2answers
577 views

mBJ-LDA band structure calculation using VASP

I tried to create a band structure with the mBJ-LDA method using VASP. I found information that the KPOINTS file should be created according to the "0-weight (...
10
votes
1answer
105 views

How to remove the fake k-points from vasprun.xml file in the calculation of HSE06 band structure?

Is there any script that can remove fake k-points from a vasprun.xml file for HSE06 band structure calculation? Because removing it manually is a time-consuming ...
15
votes
2answers
231 views

Properties that can be deduced from Band structure and DOS

Calculation of band structure and Density of States (DOS) is ubiquitous in matter modelling research publications. What are some properties that can be deduced from a band structure plot and density ...
11
votes
2answers
115 views

Separation of valence bands in transition metal dichalcogenides (TMDs)

The image below refers to a phenomenon that occurs in TMDCs (transition metal dichalcogenides) monolayers that allowed the development of valleytronics. Why are there separate bands of different ...
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 ...
11
votes
1answer
98 views

What does a density of states (DOS) plot show?

I have plotted the density of states using GGA-PBE exchange correlation functional for magnesium silcide but I really do not know what the equations involved are in this process, and how they relate ...
8
votes
1answer
64 views

How to calculate the parity of a band at a particular point in Brillouin zone

Some references mentioned that the calculation of $Z_2$ topological invariant of a crystal can be greatly simplified if the crystal contains inversion symmetry. But it involves the calculation of the ...
6
votes
2answers
255 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 ...
12
votes
1answer
142 views

Band structure and density of states disagreement (mp-19092)

My question is both specific and general. While looking through the materials project database I found this entry. The band structure reported and density of states are dramatically different it ...
6
votes
1answer
86 views

Calculating the surface state with Wannier tools

Currently I met a problem when I calculate the surface state of a topologically non-trivial thin film system. I did a DFT calculation and fit the result with wannier function. The fitting looks pretty ...
11
votes
1answer
201 views

How to start with structural defects in monolayer?

First of all, thank you for your help! You are so helpful every time. I would like to calculate the influence of the structural defects on the electronic structure in the HfS2 monolayer. With VESTA ...
8
votes
1answer
105 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 ...
11
votes
2answers
151 views

k-points value in KPOINTS file for the VASP band calculation

I'm a new VASP user, especially for the band structure calculations. I see that KPOINTS files are different for the GO/SP calculations and band calculations. For example in here it shows KPOINTS file ...
6
votes
2answers
47 views

Does SOC band structure calculations require higher number of k-grids?

In so many papers I see that they carry out soc band structure calculations with much higher kgrid than used for the geometry optimization. Whats the logic behind that?
17
votes
2answers
2k views

Calculating HSE06 band structures on Quantum ESPRESSO

I am currently trying to figure out how to compute band structures for my system, using the hybrid functional HSE06. I'm doing this on Quantum Espresso. As I understand, there are a handful of ways to ...
4
votes
1answer
60 views

How can I obtain seperate spin-up and spin-down bands while considering Spin Orbit Coupling in Quantum ESPRESSO?

I have been studying a magnetic material with SoC taken into consideration. The main aim was to obtain the band structure. when I use spin_component = 1 in the ...
11
votes
1answer
44 views

How can I properly attach ligands to a surface?

The main aim of my venture is to study the effect of the presence of surface ions on the band structure of Si slab using Quantum ESPRESSO. I've tried to use iQmol to attach ligands to the surface. The ...
5
votes
1answer
39 views

Fermi level shift downward in the thin film structure

I did a band structure calculation of a thin film structure with different number of atomic layers. I found that the original bulk gap was shifted upward and the Fermi level was shifted downward no ...
5
votes
0answers
41 views

A doubt about extended dislocation

I wonder why this phenomenon occurs: "Unlike unextended screw dislocations, the extended screw dislocations define a specific slip plane, the {111} plane of the fault and it will be constrained ...
8
votes
0answers
71 views

Band structure has unusual lines in the valence band using Quantum ESPRESSO

Currently, I am working on ZnO doped with nickel and cobalt. I performed the SCF, NCF, BANDS calculation and got the results, the calculation converges without any errors. After that I used BANDS.X to ...
7
votes
2answers
190 views

What is the meaning of the “PRIMCELL.vasp” file generated by VASPKIT tool during bandstructure inputs generation?

When I use VASPKIT tool to generate K-path KPOINTS file for Bandstructure calcualtion of a 4x4x1 supercell of a pure material, ...
10
votes
2answers
190 views

How to create a KPOINTS file (k-path) for 4x4x1 supercell bandstructure calculation?

How to generate or create the correct KPOINTS ( K-PATH) file for a 4x4x1 supercell bandstructure calculation ? Is there a software compatible with vasp can do that ?...
6
votes
0answers
65 views

Calculating the Chern number on a 2D surface of a 3D insulator

I want to calculate the Chern number of a surface of 3D time reversal insulator. I know the 3D topological insulator was characterised by the Z2 index. And the Chern number was used characterised the ...
6
votes
1answer
48 views

Band structure output from Exciting - what are the X units?

I'm using Exciting Code to calculate some electronic band structures. Starting with the example of Si I get sensible output and can plot BAND.OUT and BAND-QP.OUT using PLOT-gwbands.py or directly in ...
10
votes
1answer
139 views

Band structure of Weyl semimetal?

Weyl semimetals are topological quantum materials whose low energy excitations emerges as massles Weyl Fermions. They have a band touching point near the Fermi level called Weyl node. What is ...
10
votes
2answers
131 views

About the surface Greens function method for calculating the surface state

Currently I'm using some software package to do the data analysis from the DFT calculation so that I can study the surface state of some topological insulator. I found that the method they use is ...
9
votes
1answer
136 views

PT-symmetry leading to spin-degenerate band structures

I am trying to understand the fundamental physics of a kind of problem. I will introduce a specific example and then list some of the broader qualms I hold. I have observed many band structures, be it ...
6
votes
1answer
55 views

How to understand effect of increase in band gap generated away from Fermi energy on conductivity?

An example would be that when we dope Nitrogen in graphene its conductivity decreases. This can be explained through other means. But can this be explained through the change in its band structure?
10
votes
2answers
81 views

Spin considerations for the bandgap and optical excitations

What are the consequences for the bandgap if the conduction band edge and valence band edge are contributed by different spins? Are there any driving forces that prevent an excitation from spin up to ...
10
votes
0answers
79 views

How can I draw the energy bands for the first and second zones of Brillouin? Is it conductor or insulator? [closed]

I want to draw the energy ($E$) diagrams for a simple cubic cell of parameter $a$, where each atom provides two electrons for the almost free electron levels for planes [100], [110] and [111]. I ...
8
votes
1answer
80 views

Band theory: effective mass and Hall's coefficient

Consider the following scenario. A material has the E-k band scheme as shown in the figure (extended scheme of zones). Could anyone give me a suggestion regarding the following : Electrical character ...
13
votes
2answers
179 views

Deciding the number of CPUs for a DFT calculation for band structure in Quantum ESPRESSO?

If I am using Quantum ESPRESSO for bandstructure calculations, how can I know the number of CPUs necessary for such a calculation? I deal mostly with ternary transition metal oxides which have at ...
11
votes
1answer
586 views

Density of States of Supercells

Are there any important considerations to make for density of state calculations for supercells? With band structures typically band unfolding schemes make things easier to understand but is there ...
7
votes
0answers
216 views

Calculating band structure with HSE using Open_grid (Quantum ESPRESSO) [closed]

I have executed the SCF calculation and obtained the results. After which I used kmesh.pl to extract k-points. I was able to run wannier calculations but there was an error Checking info from wannier....
10
votes
1answer
297 views

How to model an anti-ferromagnetic crystal in quantum ESPRESSO properly?

I'm fairly new to DFT. I would like to plot the DOS and band structure of Cobalt Oxide (CoO). But since CoO is anti ferro magnetic, how would I approach the problem? would I create an input file ...