# Tag Info

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-...
• 10.4k

### 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 ...
• 4,238
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. ...
• 1,814
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 ...
• 2,931
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### 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 ...
• 396

### 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 ...
• 2,723

### 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. ...
• 14k

### 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/...
• 1,237

### 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 ...
• 2,528

### 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

• 10.4k
Accepted

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

It depends what you are trying to calculate. The possible k points that you care about are those in the first Brillouin zone. You can find a definition of that in a solid state physics textbook. In 1D ...
• 729

### Tools for working with tight-binding models

The sisl Python package can deal with Hamiltonians (and other physical matrices) in orthogonal and non-orthogonal basis sets. A simple example for graphene would be something like: ...
• 1,814