Questions tagged [tight-binding]

Questions related to the tight binding method in materials science.

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21 votes
2 answers
885 views

Derivation of Slater-Koster equations

I am trying to derive the Slater-Koster equations (Table. 1 of Ref. 1) for the two-centre approximation of hopping integrals between atomic orbitals. I understand that Slater-Koster approximates the ...
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17 votes
1 answer
3k 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 ...
  • 2,723
17 votes
1 answer
122 views

Benchmark transition state geometries in condensed phases

I'm seeking references/benchmarks for transition state geometries of reactions in condensed phases like crystals, zeolites, or surfaces. Basically the system just needs to be considered big, yet ...
  • 7,794
16 votes
1 answer
400 views

How to construct a Tight-Binding Hamiltonian from first-principles computations?

Effective Hamiltonian approaches such as the Tight-Binding method played a central role in the reconciliation between chemistry and in physics in the solid state. A classical and complete treatment of ...
16 votes
0 answers
137 views

Easy ways to generate "teaching" band structures in Python?

I'd like to introduce band structure to a class of undergraduate chemists, along the lines of Roald Hoffmann's Solids and Surfaces. That is, I'd like to start with a s-band in 1D, which is easy ...
12 votes
1 answer
346 views

DFT vs tight-binding solutions for a Dirac cone in graphene: Why is the DFT version squeezed?

I'm a beginner at DFT calculations with VASP software. I use it to calculate the band structure of graphene and I obtain the following result: I used it to calculate the band structure of graphene ...
  • 2,723
12 votes
0 answers
167 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 is characterized by the Z2 index annd that the Chern number can be used to ...
  • 2,723
12 votes
0 answers
120 views

Orbital-free DFT and Density Functional Tight-Binding: Comparison [closed]

There are many flavors of DFT that are alternative to, or go beyond the Kohn-Sham formulation (KS-DFT). Some of these are based on approximations that sacrifice accuracy when compared to KS-DFT, but ...
11 votes
1 answer
214 views

How to use wavefunctions/density to determine which orbitals lead to edge states?

I have a large matrix for a 1D zigzag edge model of an otherwise $3\times 3$ tight-binding Hamiltonian (3 basis functions, each corresponding to an atomic orbital), involving the variable $k_x$. The ...
  • 2,091
10 votes
1 answer
75 views

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

Given a tight binding matrix of a thin film system with a few atomic layers, is it possible to construct a tight binding matrix of higher atomic layers thin film from the lower one? For example, I ...
  • 2,723
9 votes
2 answers
940 views

Data format of wannier90_hr.dat from wannier90

I did a calculation on a bulk system with DFT and fit it with the tight binding matrix with wannier90. There is question on this. I try to write my own code to construct a slab tight binding matrix ...
  • 2,723
9 votes
1 answer
166 views

Evaluating Seebeck coefficient using DFT

I am working with semiconductor materials using the SIESTA DFT package. I have tried the BoltzTraP2 software interface with SIESTA, however the results (Seebeck coefficient of MgO and Si) did not ...
  • 2,528
9 votes
1 answer
132 views

Tools for working with tight-binding models

I would like to analyze a Slater-Koster tight binding model for some materials. I have the data for both the Hamiltonian as a matrix-valued map on the reciprocal lattice $H_{mn}(\vec{T})$ and the ...
  • 453
9 votes
0 answers
186 views

How to interpret WannierTools Python code that generates tight-binding model in the wannier90_hr.dat format? [closed]

I am getting myself acquainted with Wannier Tools. Wannier Tools requires two inputs, a wt.in file, and a .dat file. This ...
  • 2,091
8 votes
1 answer
107 views

Which software is suitable for visualizing the electron wavefunctions in a crystal?

I'd like to use the tight-binding model with a linear combination of atomic orbitals. It should show the full energy bands, as well as the spatial probability distribution for each eigenfunction of ...
8 votes
1 answer
243 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 ...
  • 2,723
7 votes
0 answers
41 views

The quantum spin Hall phase with Z2 = 0? [closed]

I used first principle calculations to study the thin film model. An obvious crossing was shown to appear at the gamma point when the edge state was calculated, which was originally predicted to be ...
  • 2,723
7 votes
0 answers
95 views

Construct a parity operator at a TRIM point? [closed]

I want to calculate the band parity at some TRIM (time-reversal invariant momentum) point in Brillouin zone. Parity was defined as the eigenvalue of the inversion operator. My question is how to ...
  • 2,723
6 votes
1 answer
426 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 ...
  • 2,723
6 votes
0 answers
88 views

Cheap NMR shift calculations in periodic systems

I am looking for an electronic structure method code (e.g. tight binding DFTB) that supports cheap calculations of NMR shieldings and has support for periodical systems. I would be grateful for any ...
6 votes
0 answers
62 views

Constructing the symmetry operator from k.p Hamiltonian [closed]

I have a question regarding to how to construct an operator from k.p Hamiltonian. Maybe there are some problems in my understanding, I hope you can point me out and correct my description if I made ...
  • 2,723
4 votes
0 answers
73 views

How to implement a Weyl semimetal in tight binding? [closed]

I want to study electronic and thermal transport properties of a Weyl semimetal. Until now, I have used only the continuum model hamiltonian ($H=k⋅σ$). As the continuum model has several limitations, ...
3 votes
1 answer
139 views

How to determine the concrete value for the wavenumber in tight-binding approximation

As a simple problem setting, consider a one-dimensional linear crystal of NaCl with only 1s orbitals, where the atomic distance between Na and Cl is also assumed to be 0.5 Å for simplicity (Fig. 1). ...
  • 1,647
3 votes
0 answers
18 views

boundary states of higher-order topological insulators

What are the standard computational methods used in obtaining the edge and corner states of higher-order topological insulators? From my understanding, the DFT code calculates the bulk properties of a ...
  • 453