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-...
- 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 ...
- 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.
...
- 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 ...
- 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 ...
- 406
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 ...
- 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.
...
- 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/...
- 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 ...
- 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 $l$,$m$,$...
- 61
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 ...
- 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, ...
- 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/
...
- 675
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