18 votes
Accepted

How to understand the time-reversal symmetry in graphene?

Two-band model for graphene. To simplify the discussion of Dirac points, it is sufficient to consider a nearest-neighbor tight-binding 2-band model for graphene. This is a spinless model because spin-...
user avatar
  • 10k
11 votes

Derivation of Slater-Koster equations

Spherical harmonics are not themselves full atomic orbitals. Consider the Hydrogen wave function, which separates into a radial part and an angular part. The latter is a spherical harmonic, but the ...
user avatar
  • 3,938
10 votes
Accepted

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

One way of determining this is using the projected density of states (P-DOS) This resolves the DOS into specific orbitals thereby allowing you to discretize each orbitals weight for a specific energy. ...
user avatar
  • 1,724
9 votes

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

Oh! I found the answer already. Since I'm doing the calculation along the High symmetry point. Im doing the calculation along G -> K -> M -> G, that's why the right hand sides show such phenomena. In ...
user avatar
  • 2,673
9 votes
Accepted

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

The sisl python package might be useful to you. It has: Tools to build hamiltonians with user-defined basis orbitals. A very high level API to visualize the most ...
user avatar
8 votes
Accepted

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

Yes! It is definitely possible and it is useful for calculating other things like electronic transport and first-principles values of Hubbard U (i.e. the ACBN0 method, which I have used a bit). Some ...
user avatar
  • 2,871
8 votes

Data format of wannier90_hr.dat from wannier90

The following code is a python function to read the wannier90_hr.dat, from which you should figure out its data structure. ...
user avatar
  • 13.6k
7 votes

Benchmark transition state geometries in condensed phases

Not really sure about benchmarks for solid state TS geometries. A couple of scattered piece of references are: (i) This paper by Ceder's group has several related TS barriers: aip.scitation.org/doi/...
user avatar
  • 1,227
6 votes

Evaluating Seebeck coefficient using DFT

I'm posting this here as an answer so that if anyone else runs into the same problem, they can get it clarified. After searching endlessly (because the SIESTA to BoltzTraP2 interface provided by the ...
user avatar
  • 2,454
6 votes

Derivation of Slater-Koster equations

The answer by Anyon does not address how to calculate the form of the Slater-Koster two-center integrals (2CI) but rather how to determine the direction cosines that appear in the 2CI's (the $l$,$m$,$...
user avatar
6 votes

Data format of wannier90_hr.dat from wannier90

You can read the wanniertools code. In wanniertools, to calculate surface state, they write a surfstate subroutine in surfstate.f90 file. The slab Hamiltonian is restructured from a bulk Hamiltonian ...
user avatar
  • 331
5 votes
Accepted

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

Consider the energy eigenstate $|\psi_{n\mathbf{k}}\rangle$, where $n$ is the band you are interested in and $\mathbf{k}$ is wave vector of the TRIM point. Then, if the system has inversion symmetry, ...
user avatar
  • 10k
4 votes
Accepted

Calculating the surface state with Wannier tools

Wannier90 might not be good at preserving the symmetry. But they probably include a few new methods to enforce symmetry in Wannier90.v.3.1.0. Maybe you can check this. http://www.wannier.org/features/ ...
user avatar
  • 675

Only top scored, non community-wiki answers of a minimum length are eligible